Naui Basic Diver Practice Quiz

1. After diving, your equipment should be

Placed in your dive bag and put in the closet for safe keeping

Wrung out vigorously or put in the clothes dryer

Rinsed, hung, and allowed to dry in a cool dry place

Draped over a radiator or hung near a wood stove

After diving, it is important to rinse your equipment to remove any saltwater or debris that may have accumulated. Hanging the equipment allows it to air dry properly, preventing the growth of mold or mildew. A cool dry place is ideal for drying the equipment as excessive heat can damage certain materials. This ensures that the equipment is properly cleaned and dried, ready for the next use.

Explanation

After diving, it is important to rinse your equipment to remove any saltwater or debris that may have accumulated. Hanging the equipment allows it to air dry properly, preventing the growth of mold or mildew. A cool dry place is ideal for drying the equipment as excessive heat can damage certain materials. This ensures that the equipment is properly cleaned and dried, ready for the next use.

2. Hand signals:

Must be repeatable and only used in emergencies

Are only good for checking your buddy's remaining air

Cannot be performed when wearing gloves

Must be clear, distinct, and agreed upon prior the dive

The hand signals used during a dive must be clear, distinct, and agreed upon prior to the dive. This ensures that all divers understand and can interpret the signals correctly. Clear and distinct signals are important for effective communication underwater, where verbal communication is not possible. By agreeing upon the signals beforehand, divers can ensure that they are using a standardized set of signals that everyone is familiar with. This helps to prevent confusion and miscommunication during the dive, enhancing safety and coordination among the diving team.

Explanation

The hand signals used during a dive must be clear, distinct, and agreed upon prior to the dive. This ensures that all divers understand and can interpret the signals correctly. Clear and distinct signals are important for effective communication underwater, where verbal communication is not possible. By agreeing upon the signals beforehand, divers can ensure that they are using a standardized set of signals that everyone is familiar with. This helps to prevent confusion and miscommunication during the dive, enhancing safety and coordination among the diving team.

3. Most encounters with marine animals leading to injuries occur because:

The animal is aggressive and wants to hurt you

The animal is trying to mate with you

The animal thinks you are lunch

The animal is scared of you and is trying to defend itself

Marine animals may attack and cause injuries because they are scared of humans and are trying to defend themselves. When humans approach or invade their territory, marine animals may perceive it as a threat and react aggressively in order to protect themselves. This defensive behavior is a natural response to perceived danger and is often the cause of encounters leading to injuries.

Explanation

Marine animals may attack and cause injuries because they are scared of humans and are trying to defend themselves. When humans approach or invade their territory, marine animals may perceive it as a threat and react aggressively in order to protect themselves. This defensive behavior is a natural response to perceived danger and is often the cause of encounters leading to injuries.

4. A dive knife is:

An alternative to a speargun to skewer fish

A weapon to ward off aggressive marine life

An important piece of safety equipment and a useful tool

A flashy accessory used to gain acceptance with other divers

A dive knife is an important piece of safety equipment and a useful tool because it can be used in various situations underwater. It can be used to cut through entangled fishing lines or ropes, free oneself from underwater obstacles, or even to defend against aggressive marine life if necessary. Additionally, it can serve as a versatile tool for tasks such as prying open shells or tightening equipment. Therefore, a dive knife is not just a weapon or a flashy accessory, but a practical and essential item for divers.

Explanation

A dive knife is an important piece of safety equipment and a useful tool because it can be used in various situations underwater. It can be used to cut through entangled fishing lines or ropes, free oneself from underwater obstacles, or even to defend against aggressive marine life if necessary. Additionally, it can serve as a versatile tool for tasks such as prying open shells or tightening equipment. Therefore, a dive knife is not just a weapon or a flashy accessory, but a practical and essential item for divers.

5. Special hazards that exist in and around wrecks include:

Entanglement in wreck debris

Entrapment in confined spaces

Low light/visibility

Encounters with marine life

All of the above

The special hazards that exist in and around wrecks include entrapment in confined spaces, low light/visibility, encounters with marine life, and entanglement in wreck debris. These hazards can pose significant risks to individuals exploring or working in wrecked areas. Entrapment in confined spaces can lead to difficulty in escaping or getting help. Low light/visibility can make it challenging to navigate and identify potential dangers. Encounters with marine life can result in injuries or attacks. Entanglement in wreck debris can cause injuries or restrict movement. Therefore, all of the above hazards should be considered and managed when dealing with wrecks.

Explanation

The special hazards that exist in and around wrecks include entrapment in confined spaces, low light/visibility, encounters with marine life, and entanglement in wreck debris. These hazards can pose significant risks to individuals exploring or working in wrecked areas. Entrapment in confined spaces can lead to difficulty in escaping or getting help. Low light/visibility can make it challenging to navigate and identify potential dangers. Encounters with marine life can result in injuries or attacks. Entanglement in wreck debris can cause injuries or restrict movement. Therefore, all of the above hazards should be considered and managed when dealing with wrecks.

6. Collecting marine life when diving is acceptable:

When the Marine Warden isn't nearby

As long as there is plenty more present at the dive site

It is done in accordance with local laws and understood conservation methods

Only if the marine life is to be consumed as food

Collecting marine life when diving is acceptable if it is done in accordance with local laws and understood conservation methods. This means that divers should be aware of and follow any regulations or guidelines set by the local authorities to ensure the sustainability and protection of marine ecosystems. By adhering to these laws and conservation methods, divers can minimize their impact on the marine environment while still being able to collect marine life.

Explanation

Collecting marine life when diving is acceptable if it is done in accordance with local laws and understood conservation methods. This means that divers should be aware of and follow any regulations or guidelines set by the local authorities to ensure the sustainability and protection of marine ecosystems. By adhering to these laws and conservation methods, divers can minimize their impact on the marine environment while still being able to collect marine life.

7. Low visibility at the dive site can be caused by

Silt or mud kicked up from a still bottom

Sand, powdered coral, or other particles churned up by currents/waves

Tiny organisms (plankton) floating in the water

Cloudy weather conditions

Any/all of the above

Low visibility at a dive site can be caused by any or all of the mentioned factors. Silt or mud kicked up from a still bottom can reduce visibility by suspending particles in the water. Similarly, sand, powdered coral, or other particles churned up by currents or waves can also decrease visibility. Additionally, tiny organisms like plankton floating in the water can contribute to low visibility. Cloudy weather conditions can further reduce visibility by blocking sunlight and creating a murky atmosphere. Therefore, any combination of these factors can lead to low visibility at a dive site.

Explanation

Low visibility at a dive site can be caused by any or all of the mentioned factors. Silt or mud kicked up from a still bottom can reduce visibility by suspending particles in the water. Similarly, sand, powdered coral, or other particles churned up by currents or waves can also decrease visibility. Additionally, tiny organisms like plankton floating in the water can contribute to low visibility. Cloudy weather conditions can further reduce visibility by blocking sunlight and creating a murky atmosphere. Therefore, any combination of these factors can lead to low visibility at a dive site.

8. When selecting a wet suit, key factors to consider include:

Protection from marine life, donning difficulty, seals around wrists and ankles

Color, knee padding, and zipper style

Fit, comfort, and appropriate thickness for your intended dive conditions

None of the above

The key factors to consider when selecting a wet suit include fit, comfort, and appropriate thickness for the intended dive conditions. Fit is important to ensure that the wet suit provides proper insulation and does not restrict movement. Comfort is crucial for a pleasant diving experience. The appropriate thickness of the wet suit will depend on the water temperature and the duration of the dive. These factors are essential in choosing a wet suit that will provide the necessary protection and insulation during the dive.

Explanation

The key factors to consider when selecting a wet suit include fit, comfort, and appropriate thickness for the intended dive conditions. Fit is important to ensure that the wet suit provides proper insulation and does not restrict movement. Comfort is crucial for a pleasant diving experience. The appropriate thickness of the wet suit will depend on the water temperature and the duration of the dive. These factors are essential in choosing a wet suit that will provide the necessary protection and insulation during the dive.

9. To maintain neutral buoyancy while changing depth during a dive, the diver must

Ditch weight pockets/weight belt

Add or release small squirts of air in your BCD appropriate for your diving depth

Exhale until you sink to the bottom

None of these

To maintain neutral buoyancy while changing depth during a dive, the diver must add or release small squirts of air in their BCD appropriate for their diving depth. This is because as the diver descends, the water pressure increases, causing their body and equipment to compress and become denser. By adding air to the BCD, the diver can counteract this increased density and maintain neutral buoyancy. Similarly, as the diver ascends, the water pressure decreases, causing their body and equipment to expand and become less dense. Releasing air from the BCD allows the diver to adjust their buoyancy and stay neutral throughout the dive.

Explanation

To maintain neutral buoyancy while changing depth during a dive, the diver must add or release small squirts of air in their BCD appropriate for their diving depth. This is because as the diver descends, the water pressure increases, causing their body and equipment to compress and become denser. By adding air to the BCD, the diver can counteract this increased density and maintain neutral buoyancy. Similarly, as the diver ascends, the water pressure decreases, causing their body and equipment to expand and become less dense. Releasing air from the BCD allows the diver to adjust their buoyancy and stay neutral throughout the dive.

10. True or False: If your power inflator button becomes stuck or broken, you can add air manually to your BCD to increase buoyancy.

True

False

If the power inflator button on a BCD becomes stuck or broken, it is still possible to manually add air to the BCD to increase buoyancy. This can be done by using the oral inflator, which is a separate mechanism on the BCD that allows the diver to manually inflate the BCD by blowing air into it. This can be a useful technique in emergency situations where the power inflator is not functioning properly.

Explanation

If the power inflator button on a BCD becomes stuck or broken, it is still possible to manually add air to the BCD to increase buoyancy. This can be done by using the oral inflator, which is a separate mechanism on the BCD that allows the diver to manually inflate the BCD by blowing air into it. This can be a useful technique in emergency situations where the power inflator is not functioning properly.

11. A rapid change in water temperature, typically in still or fresh water, happens at the:

Microcline

Anticline

Thermocline

Hypocline

A rapid change in water temperature, typically in still or fresh water, occurs at the thermocline. The thermocline is a layer in a body of water where there is a significant change in temperature between the warmer surface water and the colder deeper water. This change in temperature can occur quite rapidly, creating a distinct boundary between the two layers. The thermocline is important for aquatic ecosystems as it affects the distribution of oxygen and nutrients in the water, and can impact the behavior and distribution of aquatic organisms.

Explanation

A rapid change in water temperature, typically in still or fresh water, occurs at the thermocline. The thermocline is a layer in a body of water where there is a significant change in temperature between the warmer surface water and the colder deeper water. This change in temperature can occur quite rapidly, creating a distinct boundary between the two layers. The thermocline is important for aquatic ecosystems as it affects the distribution of oxygen and nutrients in the water, and can impact the behavior and distribution of aquatic organisms.

12. Dive buddies should always:

Be connected by a rope so they do not become separated

Wear matching equipment

Agree upon a leader and be in constant visual contact

Notify local rescue authorities about intended dive plans

Dive buddies should always agree upon a leader and be in constant visual contact to ensure their safety during the dive. This is important because having a designated leader helps in coordinating the dive and making decisions. Being in constant visual contact allows them to monitor each other's well-being and quickly respond in case of any emergencies or issues that may arise underwater. It helps to maintain communication and ensure that the dive buddies stay together throughout the dive, minimizing the risk of getting lost or separated.

Explanation

Dive buddies should always agree upon a leader and be in constant visual contact to ensure their safety during the dive. This is important because having a designated leader helps in coordinating the dive and making decisions. Being in constant visual contact allows them to monitor each other's well-being and quickly respond in case of any emergencies or issues that may arise underwater. It helps to maintain communication and ensure that the dive buddies stay together throughout the dive, minimizing the risk of getting lost or separated.

13. Maintaining neutral buoyancy and preventing bottom contact on a dive is important because

Bottom contact can stir up debris and reduce visibility

Touching coral, sponges or other marine organisms can easily cause harm or death to the organism

Diving at the bottom poses risk of accidental scrapes on rocks/coral and stings from marine organisms

All of the above

Maintaining neutral buoyancy and preventing bottom contact on a dive is important because it can stir up debris and reduce visibility, touching coral, sponges or other marine organisms can easily cause harm or death to the organism, and diving at the bottom poses a risk of accidental scrapes on rocks/coral and stings from marine organisms. Therefore, all of the above reasons make it crucial to maintain neutral buoyancy and avoid bottom contact during a dive.

Explanation

Maintaining neutral buoyancy and preventing bottom contact on a dive is important because it can stir up debris and reduce visibility, touching coral, sponges or other marine organisms can easily cause harm or death to the organism, and diving at the bottom poses a risk of accidental scrapes on rocks/coral and stings from marine organisms. Therefore, all of the above reasons make it crucial to maintain neutral buoyancy and avoid bottom contact during a dive.

14. Pure oxygen is a safe, harmless gas to breathe when SCUBA diving

True

False

Pure oxygen is actually not safe to breathe when SCUBA diving. Breathing pure oxygen at depths can cause oxygen toxicity, which can lead to seizures, unconsciousness, and even death. SCUBA divers typically breathe a mixture of oxygen and other gases, such as nitrogen or helium, to avoid this risk.

Explanation

Pure oxygen is actually not safe to breathe when SCUBA diving. Breathing pure oxygen at depths can cause oxygen toxicity, which can lead to seizures, unconsciousness, and even death. SCUBA divers typically breathe a mixture of oxygen and other gases, such as nitrogen or helium, to avoid this risk.

15. Decompression sickness, or "the bends" occurs when:

Divers descend too quickly and cause rupture of the eardrums

Divers ascend from depth too quickly, causing dissolved nitrogen to come out of solution in the body

Divers ascend too quickly, become disoriented and crash into the dive boat

Divers get a muscle cramp and ask their buddy to help "bend" their legs to relieve the cramps

Decompression sickness, also known as "the bends," occurs when divers ascend from depth too quickly. When divers are deep underwater, the increased pressure causes nitrogen to dissolve into their tissues and bloodstream. If they ascend too quickly, the decreased pressure causes the nitrogen to come out of solution, forming bubbles in the body. These bubbles can block blood vessels, leading to various symptoms such as joint pain, dizziness, and even organ damage. Therefore, the correct answer is that divers ascend from depth too quickly, causing dissolved nitrogen to come out of solution in the body.

Explanation

Decompression sickness, also known as "the bends," occurs when divers ascend from depth too quickly. When divers are deep underwater, the increased pressure causes nitrogen to dissolve into their tissues and bloodstream. If they ascend too quickly, the decreased pressure causes the nitrogen to come out of solution, forming bubbles in the body. These bubbles can block blood vessels, leading to various symptoms such as joint pain, dizziness, and even organ damage. Therefore, the correct answer is that divers ascend from depth too quickly, causing dissolved nitrogen to come out of solution in the body.

16. The "Giant Stride" entry is characterized by:

A backward roll into the ocean from the side of the boat

A vertical step into the ocean and away from a solid platform, such as a boat deck or flat rock

A feet-first hop from the stern of the dive boat

The waterslide off the stern of the dive boat

The "Giant Stride" entry is characterized by a vertical step into the ocean and away from a solid platform, such as a boat deck or flat rock. This means that the diver takes a step off a solid surface and enters the water in a vertical position. This entry method is commonly used when diving from a boat or a rocky shoreline, allowing the diver to enter the water smoothly and safely. It is important to enter the water in a controlled manner to avoid injuries and to maintain proper buoyancy for the dive.

Explanation

The "Giant Stride" entry is characterized by a vertical step into the ocean and away from a solid platform, such as a boat deck or flat rock. This means that the diver takes a step off a solid surface and enters the water in a vertical position. This entry method is commonly used when diving from a boat or a rocky shoreline, allowing the diver to enter the water smoothly and safely. It is important to enter the water in a controlled manner to avoid injuries and to maintain proper buoyancy for the dive.

17. Boyle's Law tells us that as we take a balloon to the bottom of a pool of fresh water, the air in the balloon

Will expand and the balloon will rupture

Will become compressed and decrease in volume

Cannot be compressed, and the balloon will rupture

Cannot be compressed and will remain unchanged.

According to Boyle's Law, the pressure and volume of a gas are inversely proportional when temperature is constant. When a balloon is taken to the bottom of a pool of fresh water, the pressure exerted by the water increases due to the weight of the water above it. As a result, the air inside the balloon will experience an increase in pressure, causing it to become compressed. Since the volume and pressure are inversely related, the decrease in pressure will lead to a decrease in volume of the air inside the balloon. Therefore, the correct answer is that the air in the balloon will become compressed and decrease in volume.

Explanation

According to Boyle's Law, the pressure and volume of a gas are inversely proportional when temperature is constant. When a balloon is taken to the bottom of a pool of fresh water, the pressure exerted by the water increases due to the weight of the water above it. As a result, the air inside the balloon will experience an increase in pressure, causing it to become compressed. Since the volume and pressure are inversely related, the decrease in pressure will lead to a decrease in volume of the air inside the balloon. Therefore, the correct answer is that the air in the balloon will become compressed and decrease in volume.

18. Which of these does not affect buoyancy?

Diver's lead in weight pockets

Diver's depth

Diver's Residual Nitrogen Time

Diver's breathing (inhaling/exhaling)

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Explanation

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19. The safe diver's motto is to "__________ your dive and then ______________ your plan"

Understand, document

Photograph, communicate

Plan, dive

Think about, remember

The safe diver's motto is to "Plan your dive and then dive your plan." This means that before starting a dive, it is important to carefully plan and prepare for it, considering factors such as depth, duration, equipment, and potential risks. Once the plan is established, the diver should then follow it during the dive, ensuring they stick to the planned route, depth limits, and safety procedures. By emphasizing the importance of planning and adhering to the plan, this motto promotes safe and responsible diving practices.

Explanation

The safe diver's motto is to "Plan your dive and then dive your plan." This means that before starting a dive, it is important to carefully plan and prepare for it, considering factors such as depth, duration, equipment, and potential risks. Once the plan is established, the diver should then follow it during the dive, ensuring they stick to the planned route, depth limits, and safety procedures. By emphasizing the importance of planning and adhering to the plan, this motto promotes safe and responsible diving practices.

20. Objects under water may appear __________________ and ____________________ than on land.

Closer, faster

Brighter, shinier

Larger, closer

Smaller, slower

Objects under water may appear larger because of the way light behaves in water. When light enters water, it slows down and bends, causing objects to appear closer than they actually are. This phenomenon, known as refraction, can make objects seem larger and closer when viewed underwater compared to when they are viewed on land.

Explanation

Objects under water may appear larger because of the way light behaves in water. When light enters water, it slows down and bends, causing objects to appear closer than they actually are. This phenomenon, known as refraction, can make objects seem larger and closer when viewed underwater compared to when they are viewed on land.

21. High-performance regulators are used:

In deep dives

In technical/commercial dives

In wreck dives

In ice diving or diving in very cold water

All of the above

High-performance regulators are designed to provide superior performance and reliability in various diving conditions. Deep dives require regulators that can deliver air at extreme depths, while technical and commercial dives often involve longer durations and higher breathing rates, necessitating regulators with enhanced airflow capabilities. Wreck dives may involve navigating through tight spaces or debris, requiring regulators with compact and streamlined designs. Lastly, diving in cold water or ice diving requires regulators that can withstand freezing temperatures and deliver air smoothly. Therefore, high-performance regulators are suitable for all the mentioned diving scenarios.

Explanation

High-performance regulators are designed to provide superior performance and reliability in various diving conditions. Deep dives require regulators that can deliver air at extreme depths, while technical and commercial dives often involve longer durations and higher breathing rates, necessitating regulators with enhanced airflow capabilities. Wreck dives may involve navigating through tight spaces or debris, requiring regulators with compact and streamlined designs. Lastly, diving in cold water or ice diving requires regulators that can withstand freezing temperatures and deliver air smoothly. Therefore, high-performance regulators are suitable for all the mentioned diving scenarios.

22. If you experience pain and cannot equalize your ears while descending for a dive, the best course of action is to:

Block your nose and blow harder until the ears pop

Immediately surface to avoid damage ear drums

Ascend until you are able to clear, then continue with your dive with more frequent ear clearing

Tough it out - it's a natural part of diving

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Explanation

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23. When you are neutrally buoyant, inhalation will cause you to ________________ and exhalation will cause you to _____________

Descend slightly, ascend slightly

Ascend slightly, descend slightly

Get dizzy, body roll

Ingas, outgas

When you are neutrally buoyant, inhalation will cause you to ascend slightly and exhalation will cause you to descend slightly. This is because when you inhale, your lungs fill with air, increasing your overall volume and buoyancy. This causes you to become slightly positively buoyant, causing you to ascend. Conversely, when you exhale, your lungs empty and your volume decreases, making you slightly negatively buoyant, causing you to descend.

Explanation

When you are neutrally buoyant, inhalation will cause you to ascend slightly and exhalation will cause you to descend slightly. This is because when you inhale, your lungs fill with air, increasing your overall volume and buoyancy. This causes you to become slightly positively buoyant, causing you to ascend. Conversely, when you exhale, your lungs empty and your volume decreases, making you slightly negatively buoyant, causing you to descend.

24. Ripples in a sandy bottom, rock formation, sun direction, and wave action are all forms of natural navigation.

True

False

The statement is true because ripples in a sandy bottom, rock formation, sun direction, and wave action are all natural elements that can be used for navigation. Ripples in a sandy bottom can indicate the direction of water flow, rock formations can serve as landmarks, the direction of the sun can help determine east and west, and wave action can provide information about the strength and direction of currents. Therefore, these natural features can be used by navigators to determine their position and direction in the absence of modern navigation tools.

Explanation

The statement is true because ripples in a sandy bottom, rock formation, sun direction, and wave action are all natural elements that can be used for navigation. Ripples in a sandy bottom can indicate the direction of water flow, rock formations can serve as landmarks, the direction of the sun can help determine east and west, and wave action can provide information about the strength and direction of currents. Therefore, these natural features can be used by navigators to determine their position and direction in the absence of modern navigation tools.

25. SCUBA cylinders should always be stored with at least a small amount of pressurized air remaining in them to:

Tell the dive shop staff they need to be refilled

Keep the valve from sticking

Keep out dust and debris

Prevent water/moisture from entering and causing rust/corrosion

Storing SCUBA cylinders with at least a small amount of pressurized air remaining in them prevents water/moisture from entering and causing rust/corrosion. When the cylinder is pressurized, it creates a barrier that prevents water or moisture from entering the cylinder. This is important because water or moisture can cause rust and corrosion, which can compromise the integrity of the cylinder and potentially lead to dangerous situations while diving. Keeping the cylinder pressurized helps to maintain its condition and prolong its lifespan.

Explanation

Storing SCUBA cylinders with at least a small amount of pressurized air remaining in them prevents water/moisture from entering and causing rust/corrosion. When the cylinder is pressurized, it creates a barrier that prevents water or moisture from entering the cylinder. This is important because water or moisture can cause rust and corrosion, which can compromise the integrity of the cylinder and potentially lead to dangerous situations while diving. Keeping the cylinder pressurized helps to maintain its condition and prolong its lifespan.

26. A mask squeeze is caused by:

Rapid ascent, decreased pressure causing your mask to loosen

Rapid descent, increased pressure forcing the mask onto your face

Accidentally inhaling water through your nose

None of the above

A mask squeeze is caused by a rapid descent, which leads to increased pressure forcing the mask onto your face. As you descend deeper underwater, the water pressure increases, and this can cause the mask to squeeze against your face. This can be uncomfortable and may even cause pain or injury if the pressure is too great. It is important to equalize the pressure in your mask by exhaling through your nose or using a mask clearing technique to prevent mask squeeze.

Explanation

A mask squeeze is caused by a rapid descent, which leads to increased pressure forcing the mask onto your face. As you descend deeper underwater, the water pressure increases, and this can cause the mask to squeeze against your face. This can be uncomfortable and may even cause pain or injury if the pressure is too great. It is important to equalize the pressure in your mask by exhaling through your nose or using a mask clearing technique to prevent mask squeeze.

27. When descending at a dive site, divers must clear their ears _______________________ and ____________________ to avoid discomfort and possible damage to ears.

Hard, quickly

Early, often

Slowly, subtlely

Quickly, quietly

When descending at a dive site, divers must clear their ears early and often to avoid discomfort and possible damage to ears. This is because as divers descend, the pressure on their ears increases. By clearing their ears early and often, divers equalize the pressure inside their ears with the surrounding water pressure, preventing discomfort and potential damage to their eardrums. This can be done by swallowing, yawning, or performing the Valsalva maneuver.

Explanation

When descending at a dive site, divers must clear their ears early and often to avoid discomfort and possible damage to ears. This is because as divers descend, the pressure on their ears increases. By clearing their ears early and often, divers equalize the pressure inside their ears with the surrounding water pressure, preventing discomfort and potential damage to their eardrums. This can be done by swallowing, yawning, or performing the Valsalva maneuver.

28. "Skip breathing" is a technique you should:

Use when deep diving to maximize bottom time

Use during decompression stops to off-gas nitrogen

Only use to minimize exhaled bubbles during underwater photography

Never use

"Skip breathing" is a technique where a diver intentionally skips breaths to conserve air while underwater. This technique is not recommended as it can lead to an increased risk of hypoxia, which is a condition of oxygen deprivation. It is important for divers to maintain a regular breathing pattern to ensure a sufficient oxygen supply and prevent any potential dangers associated with oxygen deprivation. Therefore, the correct answer is "Never use."

Explanation

"Skip breathing" is a technique where a diver intentionally skips breaths to conserve air while underwater. This technique is not recommended as it can lead to an increased risk of hypoxia, which is a condition of oxygen deprivation. It is important for divers to maintain a regular breathing pattern to ensure a sufficient oxygen supply and prevent any potential dangers associated with oxygen deprivation. Therefore, the correct answer is "Never use."

29. Mild hypothermia conditions are characterized by uncontrollable shivering, teeth chattering, and blue lips. A diver experiencing these conditions should:

Wear a hood and gloves on the next dive

Give the "chilled" sign to his/her buddy, surface, and warm up

Stand in the warm sun in the wet suit for 1 hour during the surface interval time (SIT)

Tough it out to the end of the dive - this is normal

Mild hypothermia is a condition characterized by symptoms such as uncontrollable shivering, teeth chattering, and blue lips. These symptoms indicate that the diver's body temperature has dropped significantly and immediate action is required. Giving the "chilled" sign to the buddy indicates that the diver is experiencing hypothermia and needs assistance. Surfacing and warming up is the appropriate response to prevent further cooling and to raise the diver's body temperature back to normal. Standing in the warm sun or wearing a hood and gloves may provide some relief, but they are not sufficient to address the underlying issue of hypothermia. Toughing it out to the end of the dive is not recommended as it may lead to further complications.

Explanation

Mild hypothermia is a condition characterized by symptoms such as uncontrollable shivering, teeth chattering, and blue lips. These symptoms indicate that the diver's body temperature has dropped significantly and immediate action is required. Giving the "chilled" sign to the buddy indicates that the diver is experiencing hypothermia and needs assistance. Surfacing and warming up is the appropriate response to prevent further cooling and to raise the diver's body temperature back to normal. Standing in the warm sun or wearing a hood and gloves may provide some relief, but they are not sufficient to address the underlying issue of hypothermia. Toughing it out to the end of the dive is not recommended as it may lead to further complications.

30. All of your underwater communications should be

Agreed upon in advance before the dive

Clear, distinct, and understandable even with gloves

Understood and confirmed by your buddy prior to taking action

All of the above

None of the above

The correct answer is "All of the above." This means that all of the options listed are correct explanations for how your underwater communications should be. It is important to agree upon the communication system in advance, ensure that it is clear and understandable even with gloves on, and have your buddy understand and confirm the communication before taking any action.

Explanation

The correct answer is "All of the above." This means that all of the options listed are correct explanations for how your underwater communications should be. It is important to agree upon the communication system in advance, ensure that it is clear and understandable even with gloves on, and have your buddy understand and confirm the communication before taking any action.

31. Muscle cramps in the extremities and core muscles can occur due to:

Exertion

Dehydration

Cold water

Any/All of the above

Muscle cramps in the extremities and core muscles can occur due to any or all of the mentioned factors: exertion, dehydration, and exposure to cold water. Exertion can lead to muscle fatigue and strain, increasing the likelihood of cramps. Dehydration can cause an imbalance in electrolytes, leading to muscle cramps. Cold water can also contribute to muscle cramps by causing vasoconstriction and reducing blood flow to the muscles. Therefore, any or all of these factors can contribute to the occurrence of muscle cramps.

Explanation

Muscle cramps in the extremities and core muscles can occur due to any or all of the mentioned factors: exertion, dehydration, and exposure to cold water. Exertion can lead to muscle fatigue and strain, increasing the likelihood of cramps. Dehydration can cause an imbalance in electrolytes, leading to muscle cramps. Cold water can also contribute to muscle cramps by causing vasoconstriction and reducing blood flow to the muscles. Therefore, any or all of these factors can contribute to the occurrence of muscle cramps.

32. True or False: You and your buddy hear a dive boat in the distance, and it is getting louder. You are diving with a dive flag. You should ascend immediately to the dive flag and wave to the boater to keep away from your dive site.

True

False

The correct answer is False because when you hear a dive boat in the distance and it is getting louder, you should not ascend immediately to the dive flag and wave to the boater to keep away from your dive site. Instead, you should ascend slowly and safely to the surface, while continuously monitoring your surroundings and maintaining a lookout for the boat. Once at the surface, you should signal to the boat that you are there by waving your dive flag, but you should not use it as a means to keep the boat away from your dive site. It is important to communicate with the boat and ensure that they are aware of your presence to avoid any potential accidents.

Explanation

The correct answer is False because when you hear a dive boat in the distance and it is getting louder, you should not ascend immediately to the dive flag and wave to the boater to keep away from your dive site. Instead, you should ascend slowly and safely to the surface, while continuously monitoring your surroundings and maintaining a lookout for the boat. Once at the surface, you should signal to the boat that you are there by waving your dive flag, but you should not use it as a means to keep the boat away from your dive site. It is important to communicate with the boat and ensure that they are aware of your presence to avoid any potential accidents.

33. An overexpansion injury to the lungs, or Pulmonary Over-Inflation Syndrome, is caused by:

Escape of air into the pleural cavity

Expansion of air into the tissues surrounding the heart

Damage to lung alveoli from expansion of air during a rapid ascent when the diver is holding his/her breath

None of these

An overexpansion injury to the lungs, or Pulmonary Over-Inflation Syndrome, occurs when the lung alveoli (air sacs) are damaged due to the expansion of air during a rapid ascent while holding one's breath. When a diver holds their breath and ascends quickly, the expanding air in the lungs can cause the alveoli to rupture or burst, leading to lung injuries. This is why it is important for divers to exhale continuously during ascent to prevent overexpansion injuries. The other options mentioned, such as escape of air into the pleural cavity or expansion of air into the tissues surrounding the heart, do not directly cause this specific type of lung injury.

Explanation

An overexpansion injury to the lungs, or Pulmonary Over-Inflation Syndrome, occurs when the lung alveoli (air sacs) are damaged due to the expansion of air during a rapid ascent while holding one's breath. When a diver holds their breath and ascends quickly, the expanding air in the lungs can cause the alveoli to rupture or burst, leading to lung injuries. This is why it is important for divers to exhale continuously during ascent to prevent overexpansion injuries. The other options mentioned, such as escape of air into the pleural cavity or expansion of air into the tissues surrounding the heart, do not directly cause this specific type of lung injury.

34. A regulator set has two components to regulate air pressure, called:

The first stage and the second stage

The yoke and the mouthpiece

The pre-dive knob and the purge button

The octo and the power inflator

The correct answer is "The first stage and the second stage." In scuba diving, a regulator set is used to regulate the air pressure from the tank to a breathable level. The first stage of the regulator reduces the high-pressure air from the tank to an intermediate pressure, while the second stage further reduces the pressure to a level that is comfortable for the diver to breathe. These two components work together to ensure a consistent and safe supply of air while diving.

Explanation

The correct answer is "The first stage and the second stage." In scuba diving, a regulator set is used to regulate the air pressure from the tank to a breathable level. The first stage of the regulator reduces the high-pressure air from the tank to an intermediate pressure, while the second stage further reduces the pressure to a level that is comfortable for the diver to breathe. These two components work together to ensure a consistent and safe supply of air while diving.

35. When diving a new dive site it is best to:

Just start diving and learning. Experience is the best teacher

Dive with a buddy who has experience at that site

Read a book about the dive site

Take many pictures with your underwater camera to document the site for future dives

When diving a new dive site, it is best to dive with a buddy who has experience at that site. This is because an experienced buddy can provide valuable information about the site, such as potential hazards, currents, and the best routes to take. They can also share their knowledge and help navigate the site, ensuring a safer and more enjoyable dive. Diving with an experienced buddy increases the chances of having a successful dive and reduces the risk of encountering any unforeseen difficulties.

Explanation

When diving a new dive site, it is best to dive with a buddy who has experience at that site. This is because an experienced buddy can provide valuable information about the site, such as potential hazards, currents, and the best routes to take. They can also share their knowledge and help navigate the site, ensuring a safer and more enjoyable dive. Diving with an experienced buddy increases the chances of having a successful dive and reduces the risk of encountering any unforeseen difficulties.

36. When planning repetitive dives, your ______________ dive should be your first dive

Deepest

Shallowest

Longest

Coldest

When planning repetitive dives, your deepest dive should be your first dive. This is because ascending from deeper depths requires longer decompression times compared to shallower dives. By starting with the deepest dive, you can ensure that you have enough time for decompression stops and minimize the risk of decompression sickness. Additionally, starting with the deepest dive allows you to gradually ascend to shallower depths for subsequent dives, reducing the risk of nitrogen buildup in your body.

Explanation

When planning repetitive dives, your deepest dive should be your first dive. This is because ascending from deeper depths requires longer decompression times compared to shallower dives. By starting with the deepest dive, you can ensure that you have enough time for decompression stops and minimize the risk of decompression sickness. Additionally, starting with the deepest dive allows you to gradually ascend to shallower depths for subsequent dives, reducing the risk of nitrogen buildup in your body.

37. When consuming alcoholic beverages, divers should:

Limit consuming alcohol to a few hours before diving

Abstain from alcohol for at least 12 hours before diving

Drink extra water because alcohol can lead to dehydration

Consume no more than 2 drinks or maintain .05 Blood Alcohol Content (BAC) or lower in bloodstream

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Explanation

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38. Out-of-air situations can be best avoided by:

Regularly calculating your remaining bottom time during your dive

Regularly checking your submersible pressure gauge and diving a well-designed plan

Limiting your dives to 20 minutes

Making sure your buddy always has more air than you do

Regularly checking your submersible pressure gauge and diving a well-designed plan is the best way to avoid out-of-air situations. By regularly checking the pressure gauge, you can ensure that you have enough air to complete your dive safely. Diving with a well-designed plan means that you have planned your dive properly, taking into consideration factors such as depth, time, and air consumption. This helps in managing your air supply effectively and prevents running out of air during the dive.

Explanation

Regularly checking your submersible pressure gauge and diving a well-designed plan is the best way to avoid out-of-air situations. By regularly checking the pressure gauge, you can ensure that you have enough air to complete your dive safely. Diving with a well-designed plan means that you have planned your dive properly, taking into consideration factors such as depth, time, and air consumption. This helps in managing your air supply effectively and prevents running out of air during the dive.

39. What is meant by "residual nitrogen?"

The calculation of nitrogen gas remaining in your cylinder at the end of your dive

The small amount of nitrogen remaining in blended gasses like nitrox or trimix

The remaining 500 PSI of air in your cylinder at the end of your dive

The amount of excess nitrogen remaining in your body after diving

Residual nitrogen refers to the amount of excess nitrogen that remains in the body after diving. When diving, the body absorbs nitrogen from the compressed air inhaled. During ascent, the body needs to eliminate this excess nitrogen gradually to avoid decompression sickness. The concept of residual nitrogen is crucial in dive planning and determining surface intervals between dives to ensure safe decompression.

Explanation

Residual nitrogen refers to the amount of excess nitrogen that remains in the body after diving. When diving, the body absorbs nitrogen from the compressed air inhaled. During ascent, the body needs to eliminate this excess nitrogen gradually to avoid decompression sickness. The concept of residual nitrogen is crucial in dive planning and determining surface intervals between dives to ensure safe decompression.

40. As you ascend from a dive, any air remaining in your BCD will:

Remain unchanged

Expand and become more buoyant

Compress and become less buoyant

Likely to burst your BDC or cause an uncontrolled ascent to the surface

As you ascend from a dive, the pressure surrounding your BCD decreases. This decrease in pressure causes any air remaining in the BCD to expand. As the air expands, it takes up more space and becomes less dense, making it more buoyant. This increased buoyancy helps to counteract the weight of the diver and their equipment, allowing for a controlled ascent.

Explanation

As you ascend from a dive, the pressure surrounding your BCD decreases. This decrease in pressure causes any air remaining in the BCD to expand. As the air expands, it takes up more space and becomes less dense, making it more buoyant. This increased buoyancy helps to counteract the weight of the diver and their equipment, allowing for a controlled ascent.

41. Cloudy conditions at the dive site will:

Increase visibility

Decrease visibility

Decrease water temperature

Improve marine life sightings

Cloudy conditions at a dive site will decrease visibility because clouds block sunlight from reaching the water's surface, resulting in reduced light penetration. This reduces the amount of light available for divers to see underwater, making it harder to see clearly and decreasing visibility.

Explanation

Cloudy conditions at a dive site will decrease visibility because clouds block sunlight from reaching the water's surface, resulting in reduced light penetration. This reduces the amount of light available for divers to see underwater, making it harder to see clearly and decreasing visibility.

42. After a week of diving at the resort, you should wait ___________________ before flying home.

12 hours

24 hours

3 days

7 days

After a week of diving at the resort, you should wait 24 hours before flying home. This is because diving can cause the body to absorb nitrogen, which can lead to decompression sickness if not given enough time to safely release from the body. Waiting 24 hours allows the body to eliminate the excess nitrogen and reduces the risk of decompression sickness during the flight.

Explanation

After a week of diving at the resort, you should wait 24 hours before flying home. This is because diving can cause the body to absorb nitrogen, which can lead to decompression sickness if not given enough time to safely release from the body. Waiting 24 hours allows the body to eliminate the excess nitrogen and reduces the risk of decompression sickness during the flight.

43. Naturally occurring magnetic minerals (such as magnetite) in rocks/ledge on the bottom can throw off your compass, making compass navigation more difficult.

True

False

The presence of naturally occurring magnetic minerals, like magnetite, in rocks or ledges on the bottom can cause interference with a compass. This interference can disrupt the accuracy of the compass needle, making it more challenging to navigate using a compass. Therefore, the statement is true.

Explanation

The presence of naturally occurring magnetic minerals, like magnetite, in rocks or ledges on the bottom can cause interference with a compass. This interference can disrupt the accuracy of the compass needle, making it more challenging to navigate using a compass. Therefore, the statement is true.

44. Divers should breathe ______________________ and ___________________ than they would on land.

Slower, shallower

Quicker, shallower

Slower, deeper

Quicker, deeper

When diving, divers should breathe slower and deeper than they would on land. This is because the pressure underwater can affect the way our bodies absorb oxygen. Breathing slower allows for more efficient gas exchange in the lungs, while breathing deeper ensures that enough oxygen is taken in to meet the body's needs. Additionally, breathing slower and deeper helps to conserve air and extend the dive time.

Explanation

When diving, divers should breathe slower and deeper than they would on land. This is because the pressure underwater can affect the way our bodies absorb oxygen. Breathing slower allows for more efficient gas exchange in the lungs, while breathing deeper ensures that enough oxygen is taken in to meet the body's needs. Additionally, breathing slower and deeper helps to conserve air and extend the dive time.

45. A diver should never allow SCUBA cylinders to:

Be stacked for fear of breakage

Overheat in cars or while in storage

Be painted or covered in adhesive decals

Be taken apart for internal visual inspection

SCUBA cylinders should never be allowed to overheat in cars or while in storage. Overheating can cause the pressure inside the cylinder to increase, which can lead to a rupture or explosion. It is important to store SCUBA cylinders in a cool and well-ventilated area to prevent overheating. Additionally, leaving them in a car on a hot day can also cause overheating and should be avoided. Proper storage and handling of SCUBA cylinders is crucial for diver safety.

Explanation

SCUBA cylinders should never be allowed to overheat in cars or while in storage. Overheating can cause the pressure inside the cylinder to increase, which can lead to a rupture or explosion. It is important to store SCUBA cylinders in a cool and well-ventilated area to prevent overheating. Additionally, leaving them in a car on a hot day can also cause overheating and should be avoided. Proper storage and handling of SCUBA cylinders is crucial for diver safety.

46. There is no need to wear a wet suit or skin suit when diving in a tropical destination, since the water will be so warm

True

False

This statement is false because even in tropical destinations, the water temperature can vary and may not always be warm enough to dive comfortably without a wet suit or skin suit. Divers often wear wet suits to protect themselves from cold water, jellyfish stings, and other potential hazards. Therefore, it is incorrect to assume that a wet suit or skin suit is not needed when diving in a tropical destination solely based on the assumption that the water will always be warm.

Explanation

This statement is false because even in tropical destinations, the water temperature can vary and may not always be warm enough to dive comfortably without a wet suit or skin suit. Divers often wear wet suits to protect themselves from cold water, jellyfish stings, and other potential hazards. Therefore, it is incorrect to assume that a wet suit or skin suit is not needed when diving in a tropical destination solely based on the assumption that the water will always be warm.

47. If you run out of air while diving with your buddy and do not have equipment for contingency scuba, the best course of action is to:

Buddy breathe and use your manual inflator in your BCD to get to the surface as quickly as possible

Hold your breath and ascend as quickly as possible

Give the out of air sign and breathe off your buddy's alternate air source (octopus 2nd stage regulator)

None of the above

In the given scenario, if you run out of air while diving and do not have contingency scuba equipment, the best course of action would be to give the out of air sign and breathe off your buddy's alternate air source (octopus 2nd stage regulator). This is because your buddy's alternate air source can provide you with the necessary air to continue breathing underwater until you can safely ascend to the surface. Buddy breathing is a common technique used in emergency situations to share air with a diving partner.

Explanation

In the given scenario, if you run out of air while diving and do not have contingency scuba equipment, the best course of action would be to give the out of air sign and breathe off your buddy's alternate air source (octopus 2nd stage regulator). This is because your buddy's alternate air source can provide you with the necessary air to continue breathing underwater until you can safely ascend to the surface. Buddy breathing is a common technique used in emergency situations to share air with a diving partner.

48. The parts of the ear affected by changes in pressure from diving are:

The tympanic cavity and the auditory nerve

The ear drum and the eustachian tube

The cochlea and the ossicles (semi-circular canals)

The peristaltic nerve and the sinusoidal passage

When diving, changes in pressure can affect the ear drum and the eustachian tube. The ear drum, also known as the tympanic membrane, is a thin, sensitive membrane that separates the outer ear from the middle ear. It vibrates in response to sound waves and transmits them to the middle ear. The eustachian tube, on the other hand, is a narrow tube that connects the middle ear to the back of the throat. It helps equalize the pressure between the middle ear and the environment, allowing the ear drum to function properly. Changes in pressure during diving can cause the ear drum to become stretched or damaged, and can also lead to blockages or dysfunction in the eustachian tube, resulting in discomfort or even hearing loss.

Explanation

When diving, changes in pressure can affect the ear drum and the eustachian tube. The ear drum, also known as the tympanic membrane, is a thin, sensitive membrane that separates the outer ear from the middle ear. It vibrates in response to sound waves and transmits them to the middle ear. The eustachian tube, on the other hand, is a narrow tube that connects the middle ear to the back of the throat. It helps equalize the pressure between the middle ear and the environment, allowing the ear drum to function properly. Changes in pressure during diving can cause the ear drum to become stretched or damaged, and can also lead to blockages or dysfunction in the eustachian tube, resulting in discomfort or even hearing loss.

49. A diver's buoyancy goal throughout a dive is to:

Get negatively buoyant as quickly as possible to descend to depth

Get positively buoyant as quickly as possible to ascend to the surface

Remain neutrally buoyant regardless of depth for the duration of the dive

Remain at the same buoyancy compared to your buddy so you never get lost or separated

Keep exactly the same amount of air in the BCD to maintain neutral buoyancy, regardless of depth

The correct answer is to remain neutrally buoyant regardless of depth for the duration of the dive. This means that the diver should adjust their buoyancy to be neither sinking nor floating, allowing them to maintain a stable position in the water column. This is important for maintaining control and conserving energy during the dive, as well as for minimizing the impact on the underwater environment.

Explanation

The correct answer is to remain neutrally buoyant regardless of depth for the duration of the dive. This means that the diver should adjust their buoyancy to be neither sinking nor floating, allowing them to maintain a stable position in the water column. This is important for maintaining control and conserving energy during the dive, as well as for minimizing the impact on the underwater environment.

50. If you are feeling short of breath on a dive, you must ________________________, ______________________ and ______________________.

Stop using your arms, breathe rapidly to increase oxygen, and ascend

Stop swimming, check your regulator, and ask your buddy to turn your SCUBA cylinder on more

Stop, ditch weight, and tell your buddy to slow down

Stop swimming, rest, and breathe deeply

When feeling short of breath on a dive, it is important to stop swimming to conserve energy and rest. By resting, the body can recover and regain control of breathing. Breathing deeply helps to increase oxygen intake and alleviate the feeling of breathlessness.

Explanation

When feeling short of breath on a dive, it is important to stop swimming to conserve energy and rest. By resting, the body can recover and regain control of breathing. Breathing deeply helps to increase oxygen intake and alleviate the feeling of breathlessness.

51. As a diver descends, his or her neoprene wet suit will become compressed, slightly reducing its insulating value and making it less buoyant.

True

False

As a diver descends deeper into the water, the pressure increases, causing the neoprene wet suit to compress. This compression reduces the amount of air trapped within the suit's fabric, which in turn decreases its insulating value. With less insulation, the wet suit is less effective in keeping the diver warm. Additionally, the compression of the wet suit also reduces its buoyancy, making the diver slightly less buoyant in the water. Therefore, the statement is true.

Explanation

As a diver descends deeper into the water, the pressure increases, causing the neoprene wet suit to compress. This compression reduces the amount of air trapped within the suit's fabric, which in turn decreases its insulating value. With less insulation, the wet suit is less effective in keeping the diver warm. Additionally, the compression of the wet suit also reduces its buoyancy, making the diver slightly less buoyant in the water. Therefore, the statement is true.

52. Advanced Diver is a course designed for newly certified divers who want to enhance their diving skills in areas such as compass navigation, advanced entries/exits, and deeper diving.

True

False

The statement is explaining that the Advanced Diver course is intended for newly certified divers who wish to improve their diving abilities in various areas such as compass navigation, advanced entries/exits, and deeper diving. Therefore, the correct answer is True, indicating that the statement is accurate.

Explanation

The statement is explaining that the Advanced Diver course is intended for newly certified divers who wish to improve their diving abilities in various areas such as compass navigation, advanced entries/exits, and deeper diving. Therefore, the correct answer is True, indicating that the statement is accurate.

53. It's important to maintain a logbook because:

It serves as a record of your dive training and experiences

It proves to other divers you are just as good as the others in the group

Divemasters or instructors who do not know you may ask to see it

A & C above

Maintaining a logbook is important because it serves as a record of your dive training and experiences. It allows you to keep track of the dives you have completed, the skills you have acquired, and the conditions you have encountered. Additionally, divemasters or instructors who are not familiar with you may ask to see your logbook to assess your diving experience and proficiency. Therefore, having a logbook is beneficial both for personal reference and for demonstrating your diving abilities to others.

Explanation

Maintaining a logbook is important because it serves as a record of your dive training and experiences. It allows you to keep track of the dives you have completed, the skills you have acquired, and the conditions you have encountered. Additionally, divemasters or instructors who are not familiar with you may ask to see your logbook to assess your diving experience and proficiency. Therefore, having a logbook is beneficial both for personal reference and for demonstrating your diving abilities to others.

54. An unforeseen rip current threatens to take you and your dive buddy far away from your planned exit point. You should:

Deflate your BCD and swim across the current as hard and fast as possible to get through it

Inflate your BCD and swim parallel to the shore until you can reach a safe exit point

Deflate your BCD and belly crawl along the bottom until you are in shallow enough water to stand

Inflate your BCD and swim away from shore and wait to be picked up by the coast guard

Inflating the BCD and swimming parallel to the shore is the correct answer because it allows you to conserve energy and avoid being pulled further away by the rip current. By swimming parallel to the shore, you can eventually reach a point where the current is weaker and then swim towards the shore to exit safely. Deflating the BCD and swimming across the current may exhaust you and make it difficult to make progress, while belly crawling along the bottom may not be feasible in deeper water. Waiting to be picked up by the coast guard is not recommended as it may take time for them to arrive, and you should try to reach safety on your own if possible.

Explanation

Inflating the BCD and swimming parallel to the shore is the correct answer because it allows you to conserve energy and avoid being pulled further away by the rip current. By swimming parallel to the shore, you can eventually reach a point where the current is weaker and then swim towards the shore to exit safely. Deflating the BCD and swimming across the current may exhaust you and make it difficult to make progress, while belly crawling along the bottom may not be feasible in deeper water. Waiting to be picked up by the coast guard is not recommended as it may take time for them to arrive, and you should try to reach safety on your own if possible.

55. Repeated immersion in salt water (like on a dive trip) can cause an eczema-like condition called neurodermatitis or atopic dermatitis, with symptoms such as itchy and flaky skin and red, rashy bumps. The best way to deal this condition is to:

Wear a full neoprene wet suit on every dive to prevent salt water from reaching the skin

Wash vigorously with an exfoliating soap scrub to remove accumulated salt and dead skin cells

Rinse off with fresh water, apply skin moisturizer after every dive, use only mild soap, and limit direct sun exposure

Tough it out, there is no treatment

Repeated immersion in salt water can lead to a condition called neurodermatitis or atopic dermatitis, which causes itchy and flaky skin with red, rashy bumps. The best way to deal with this condition is to rinse off with fresh water after every dive to remove salt, apply skin moisturizer to keep the skin hydrated, use only mild soap to avoid further irritation, and limit direct sun exposure to prevent aggravation of the symptoms.

Explanation

Repeated immersion in salt water can lead to a condition called neurodermatitis or atopic dermatitis, which causes itchy and flaky skin with red, rashy bumps. The best way to deal with this condition is to rinse off with fresh water after every dive to remove salt, apply skin moisturizer to keep the skin hydrated, use only mild soap to avoid further irritation, and limit direct sun exposure to prevent aggravation of the symptoms.

56. Air in a standard scuba cylinder is comprised of:

78% Nitrogen, 21% Oxygen, and many trace gasses

70% Nitrogen, 20% Oxygen, 10% Carbon Dioxide, and trace gasses

Roughly equal parts of Nitrogen, Oxygen, Helium and trace gasses

None of these

The air in a standard scuba cylinder is comprised of 78% Nitrogen, 21% Oxygen, and many trace gases. This composition is commonly used in scuba diving because it closely resembles the composition of the Earth's atmosphere. Nitrogen is the most abundant gas in the air, while oxygen is essential for respiration. The trace gases present in the air can vary, but they are typically present in very small amounts and do not significantly affect the overall composition.

Explanation

The air in a standard scuba cylinder is comprised of 78% Nitrogen, 21% Oxygen, and many trace gases. This composition is commonly used in scuba diving because it closely resembles the composition of the Earth's atmosphere. Nitrogen is the most abundant gas in the air, while oxygen is essential for respiration. The trace gases present in the air can vary, but they are typically present in very small amounts and do not significantly affect the overall composition.

57. When turning on your SCUBA cylinder:

Crack the valve open just a little bit to conserve air

Rotate the on/off knob clockwise until it stops

Rotate the on/off knob counterclockwise until it stops and then turn clockwise one-quarter turn

Keep the air turned off until you get to the bottom and then ask your buddy to turn it on

To turn on your SCUBA cylinder, you need to rotate the on/off knob counterclockwise until it stops. This action ensures that the valve is fully open. After reaching the stopping point, you then need to turn the knob clockwise one-quarter turn to secure it in the open position. This additional clockwise turn ensures that the valve is properly locked and prevents accidental closing during the dive.

Explanation

To turn on your SCUBA cylinder, you need to rotate the on/off knob counterclockwise until it stops. This action ensures that the valve is fully open. After reaching the stopping point, you then need to turn the knob clockwise one-quarter turn to secure it in the open position. This additional clockwise turn ensures that the valve is properly locked and prevents accidental closing during the dive.

58. "Rapture of the Deep" is an intoxicated, euphoric feeling sometimes experienced by divers, which is more formally known as:

Decompression Sickness (DCS)

Pneumothorax

Pulminary Embollism

Nitrogen Narcosis

Nitrogen Narcosis is the correct answer because it refers to the intoxicated, euphoric feeling experienced by divers at great depths. This condition occurs due to the increased pressure of nitrogen in the bloodstream, leading to symptoms similar to alcohol intoxication. It is important for divers to be aware of this condition as it can impair judgment and coordination, potentially leading to dangerous situations underwater.

Explanation

Nitrogen Narcosis is the correct answer because it refers to the intoxicated, euphoric feeling experienced by divers at great depths. This condition occurs due to the increased pressure of nitrogen in the bloodstream, leading to symptoms similar to alcohol intoxication. It is important for divers to be aware of this condition as it can impair judgment and coordination, potentially leading to dangerous situations underwater.

59. A principal threat to divers from air cylinders filled at non-certified locations is:

Overfilling which may cause damage to burst discs

Failure to perform the required annual inspections

Air impurity that may include harmful gasses, such as carbon monoxide

None of the above

Air impurity that may include harmful gases, such as carbon monoxide, is a principal threat to divers from air cylinders filled at non-certified locations. Carbon monoxide is a poisonous gas that can cause serious health issues and even death when breathed in at high concentrations. Non-certified locations may not have proper procedures in place to ensure the purity of the air being filled into the cylinders, increasing the risk to divers. It is important for divers to ensure that their air cylinders are filled at certified locations to minimize the risk of exposure to harmful gases.

Explanation

Air impurity that may include harmful gases, such as carbon monoxide, is a principal threat to divers from air cylinders filled at non-certified locations. Carbon monoxide is a poisonous gas that can cause serious health issues and even death when breathed in at high concentrations. Non-certified locations may not have proper procedures in place to ensure the purity of the air being filled into the cylinders, increasing the risk to divers. It is important for divers to ensure that their air cylinders are filled at certified locations to minimize the risk of exposure to harmful gases.

60. When ascending to the surface, you should:

Ditch your weight, fully inflate your BCD, and get to the surface as quickly as possible

Hold your buddy's arm as you ascend so you don't get lost or separated

Hold up a hand, look up, and swim to the surface

When ascending to the surface, it is important to hold up a hand, look up, and swim to the surface. This is a standard safety procedure in scuba diving known as the "safety stop." By holding up a hand, you signal to your buddy and other divers that you are ascending. Looking up helps you maintain awareness of your surroundings and avoid any obstacles. Swimming to the surface allows for a controlled ascent, preventing rapid changes in pressure that can lead to decompression sickness.

Explanation

When ascending to the surface, it is important to hold up a hand, look up, and swim to the surface. This is a standard safety procedure in scuba diving known as the "safety stop." By holding up a hand, you signal to your buddy and other divers that you are ascending. Looking up helps you maintain awareness of your surroundings and avoid any obstacles. Swimming to the surface allows for a controlled ascent, preventing rapid changes in pressure that can lead to decompression sickness.

61. A small group dives a wreck in 130 feet of water for 25 minutes. They complete a 10 minute decompression stop before surfacing for a 30 minute surface interval. Knowing that their deepest dive should be first, they discuss diving a second nearby wreck at 110 feet. Their Adjusted Maximum Dive Time for the repetitive dive would be __________.

30 minutes

19 minutes

36 minutes

Repetitive dives over 100 feet are not recommended using NAUI dive tables.

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Explanation

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62. When using NAUI dive tables, you can round times and depths up or down to whichever value on the chart is closest to actual.

True

False

When using NAUI dive tables, you cannot round times and depths up or down to the closest value on the chart. NAUI dive tables require divers to always round up to the next higher value. Therefore, the statement that you can round times and depths to whichever value on the chart is closest to actual is false.

Explanation

When using NAUI dive tables, you cannot round times and depths up or down to the closest value on the chart. NAUI dive tables require divers to always round up to the next higher value. Therefore, the statement that you can round times and depths to whichever value on the chart is closest to actual is false.

63. Salt water is:

Denser and heavier than fresh water, making you more bouyant

Denser and heavier than fresh water, making you less bouyant

Less dense/lighter than fresh water, making you less bouyant

Less dense/lighter than fresh water, making you more bouyant

Salt water is denser and heavier than fresh water because it contains a higher concentration of dissolved salts and minerals. This increased density makes objects more buoyant in salt water compared to fresh water. When an object is placed in salt water, it experiences an upward force due to the difference in density, which makes it easier to float or stay afloat. Therefore, salt water makes you more buoyant.

Explanation

Salt water is denser and heavier than fresh water because it contains a higher concentration of dissolved salts and minerals. This increased density makes objects more buoyant in salt water compared to fresh water. When an object is placed in salt water, it experiences an upward force due to the difference in density, which makes it easier to float or stay afloat. Therefore, salt water makes you more buoyant.

64. You should have your regulator serviced by a certified technician:

Monthly

Annually

Every 5 years

After any dive exceeding 20 meters (66 feet)

Regulators are important equipment for scuba diving, as they control the flow of air from the tank to the diver. Regular servicing by a certified technician ensures that the regulator is functioning properly and is safe to use. Annual servicing allows for the inspection and maintenance of the regulator's various components, including the valves, hoses, and diaphragms. This helps to prevent any potential malfunctions or failures that could occur during a dive, ensuring the diver's safety. Therefore, it is recommended to have the regulator serviced annually.

Explanation

Regulators are important equipment for scuba diving, as they control the flow of air from the tank to the diver. Regular servicing by a certified technician ensures that the regulator is functioning properly and is safe to use. Annual servicing allows for the inspection and maintenance of the regulator's various components, including the valves, hoses, and diaphragms. This helps to prevent any potential malfunctions or failures that could occur during a dive, ensuring the diver's safety. Therefore, it is recommended to have the regulator serviced annually.

65. Divers are at risk of heat stroke when:

They dive too close to the surface on sunny days

They put on their wet/dry suits too early before a dive on a warm or sunny day

They pour hot water down their wetsuit to stay warm

None of the above

Divers are at risk of heat stroke when they put on their wet/dry suits too early before a dive on a warm or sunny day. This is because wet/dry suits are designed to insulate the body and retain heat. Wearing them too early can cause the body to overheat, especially in warm or sunny conditions. Heat stroke occurs when the body's temperature regulation system fails, leading to dangerously high body temperatures. Therefore, putting on wet/dry suits too early in such conditions increases the risk of heat stroke for divers.

Explanation

Divers are at risk of heat stroke when they put on their wet/dry suits too early before a dive on a warm or sunny day. This is because wet/dry suits are designed to insulate the body and retain heat. Wearing them too early can cause the body to overheat, especially in warm or sunny conditions. Heat stroke occurs when the body's temperature regulation system fails, leading to dangerously high body temperatures. Therefore, putting on wet/dry suits too early in such conditions increases the risk of heat stroke for divers.

66. Whenever you remove your regulator set from the SCUBA cylinder after a dive, the first thing you should do is:

Dunk it in the wash basin on the dock or at the dive shop

Rinse off the whole set in the ocean

Coil it up and gently put it into your dive bag

Fasten the dust cap over the inlet port to prevent moisture/debris from entering the regulator set

The correct answer is to fasten the dust cap over the inlet port to prevent moisture/debris from entering the regulator set. This is important because moisture and debris can damage the internal components of the regulator set, leading to malfunction or failure. By securely fastening the dust cap, you can protect the regulator set and ensure its proper functioning for future dives.

Explanation

The correct answer is to fasten the dust cap over the inlet port to prevent moisture/debris from entering the regulator set. This is important because moisture and debris can damage the internal components of the regulator set, leading to malfunction or failure. By securely fastening the dust cap, you can protect the regulator set and ensure its proper functioning for future dives.

67. During a deep dive, a diver experiences nitrogen narcosis. Which of the following actions should the diver take to safely manage the situation?

Increase the depth of the dive to acclimate to the condition

Ascend to a shallower depth to reduce the effects of nitrogen narcosis

Continue the dive at the current depth while monitoring the symptoms

Inflate the buoyancy control device (BCD) fully and ascend rapidly to the surface

Nitrogen narcosis occurs when nitrogen, under high pressure at depth, has a narcotic effect on the brain. The best way to manage this is to ascend to a shallower depth, where the pressure is reduced, thereby alleviating the symptoms. Increasing the depth (option A) or continuing at the current depth (option C) could worsen the condition, and a rapid ascent (option D) could lead to decompression sickness, which is dangerous.

Explanation

Nitrogen narcosis occurs when nitrogen, under high pressure at depth, has a narcotic effect on the brain. The best way to manage this is to ascend to a shallower depth, where the pressure is reduced, thereby alleviating the symptoms. Increasing the depth (option A) or continuing at the current depth (option C) could worsen the condition, and a rapid ascent (option D) could lead to decompression sickness, which is dangerous.

68. You hold onto the D-rings on your buddy's BCD when buddy breathing because

Physical contact with your buddy can help calm him or her down from a panicked state

It makes it easier to maintain face-to-face orientation so it is easier to share the regulator

You do not want to become separated by currents or accidental kicks

All of the above

All of the above. When buddy breathing, holding onto the D-rings on your buddy's BCD serves multiple purposes. Firstly, physical contact can help calm a panicked buddy down, providing reassurance and support. Secondly, maintaining face-to-face orientation becomes easier, allowing for better communication and sharing of the regulator. Lastly, holding onto the D-rings prevents accidental separation due to currents or accidental kicks, ensuring that both buddies stay together during the dive.

Explanation

All of the above. When buddy breathing, holding onto the D-rings on your buddy's BCD serves multiple purposes. Firstly, physical contact can help calm a panicked buddy down, providing reassurance and support. Secondly, maintaining face-to-face orientation becomes easier, allowing for better communication and sharing of the regulator. Lastly, holding onto the D-rings prevents accidental separation due to currents or accidental kicks, ensuring that both buddies stay together during the dive.

69. An organization that can help you in case of an accident or dive related emergency is:

NAUI

PADI

DAN

SSI

DAN stands for Divers Alert Network, which is an organization that provides emergency medical assistance and resources for scuba divers and other water-related emergencies. They offer a 24/7 emergency hotline, medical information, insurance coverage, and research to promote diver safety. DAN is widely recognized and respected in the diving community for their expertise and support in case of accidents or dive-related emergencies.

Explanation

DAN stands for Divers Alert Network, which is an organization that provides emergency medical assistance and resources for scuba divers and other water-related emergencies. They offer a 24/7 emergency hotline, medical information, insurance coverage, and research to promote diver safety. DAN is widely recognized and respected in the diving community for their expertise and support in case of accidents or dive-related emergencies.

70. A dry suit is used for:

Cold water conditions

Diving in areas with possible pollutants

Technical diving

Any/all of the above

A dry suit is a type of diving suit that provides insulation and keeps the diver dry. It is used in various situations, including diving in areas with possible pollutants, technical diving, and cold water conditions. The suit's design prevents water from entering, allowing the diver to stay warm and protected from the elements. Therefore, the correct answer is "Any/all of the above" as all the mentioned situations require the use of a dry suit.

Explanation

A dry suit is a type of diving suit that provides insulation and keeps the diver dry. It is used in various situations, including diving in areas with possible pollutants, technical diving, and cold water conditions. The suit's design prevents water from entering, allowing the diver to stay warm and protected from the elements. Therefore, the correct answer is "Any/all of the above" as all the mentioned situations require the use of a dry suit.

71. The benefit of the Push method of tired diver recovery, where the rescuer pushes the tired diver while holding the tired diver's fins to their shoulders include:

The ability to look into the tired diver's face to assess consciousness or shock

The ability to swim in a more streamlined manner to cover more distance

The ability to steer and control your buddy in the water

All of the above

The Push method of tired diver recovery, where the rescuer pushes the tired diver while holding the tired diver's fins to their shoulders, offers several benefits. Firstly, it allows the rescuer to look into the tired diver's face, enabling them to assess the diver's level of consciousness or shock. Additionally, by holding the diver's fins to their shoulders, the rescuer can swim in a more streamlined manner, covering more distance efficiently. Lastly, this method provides the rescuer with the ability to steer and control their buddy in the water, ensuring their safety during the recovery process.

Explanation

The Push method of tired diver recovery, where the rescuer pushes the tired diver while holding the tired diver's fins to their shoulders, offers several benefits. Firstly, it allows the rescuer to look into the tired diver's face, enabling them to assess the diver's level of consciousness or shock. Additionally, by holding the diver's fins to their shoulders, the rescuer can swim in a more streamlined manner, covering more distance efficiently. Lastly, this method provides the rescuer with the ability to steer and control their buddy in the water, ensuring their safety during the recovery process.

72. In a shore dive situation, you should don your fins

At your car so you can sit down and fasten them properly

On the bottom after you swim through the surf zone

In chest-deep water away from breaking waves

Any of the above is acceptable

In a shore dive situation, it is recommended to don your fins in chest-deep water away from breaking waves. This is because donning your fins at your car may be inconvenient and sitting down to fasten them properly could be difficult in a sandy or rocky area. Swimming through the surf zone before putting on your fins can be risky and challenging due to the breaking waves. Therefore, the safest and most practical option is to put on your fins in chest-deep water away from the breaking waves.

Explanation

In a shore dive situation, it is recommended to don your fins in chest-deep water away from breaking waves. This is because donning your fins at your car may be inconvenient and sitting down to fasten them properly could be difficult in a sandy or rocky area. Swimming through the surf zone before putting on your fins can be risky and challenging due to the breaking waves. Therefore, the safest and most practical option is to put on your fins in chest-deep water away from the breaking waves.

73. When buddy breathing using a single, second-stage regulator, it is most important to:

Maintain control of one's own air source (regulator)

Give your buddy as much air as he or she needs to calm down

Ascend as quickly as possible, even if it means risking "the bends."

Hold your breath tightly when your buddy is breathing off your regulator

When buddy breathing using a single, second-stage regulator, it is most important to maintain control of one's own air source (regulator). This means that each diver should hold onto their own regulator and not let go of it, ensuring that they have a continuous supply of air. This is crucial for their safety and allows them to have control over their own breathing and air consumption. It also ensures that they can respond to any emergency situations that may arise during the dive.

Explanation

When buddy breathing using a single, second-stage regulator, it is most important to maintain control of one's own air source (regulator). This means that each diver should hold onto their own regulator and not let go of it, ensuring that they have a continuous supply of air. This is crucial for their safety and allows them to have control over their own breathing and air consumption. It also ensures that they can respond to any emergency situations that may arise during the dive.

74. Most surface waves in the ocean are caused by:

Tides

Large boats running offshore

Wind

Earthquakes

Surface waves in the ocean are primarily caused by wind. As wind blows across the surface of the water, it creates friction and transfers energy to the water, causing the water to move in a wave-like motion. This is why surface waves are most commonly observed in areas with strong winds. While large boats running offshore can create waves, they are not as common or widespread as those caused by wind. Earthquakes can also generate waves in the ocean, known as tsunamis, but these are less frequent and have different characteristics than surface waves. Tides, on the other hand, are caused by the gravitational pull of the moon and sun and do not directly create surface waves.

Explanation

Surface waves in the ocean are primarily caused by wind. As wind blows across the surface of the water, it creates friction and transfers energy to the water, causing the water to move in a wave-like motion. This is why surface waves are most commonly observed in areas with strong winds. While large boats running offshore can create waves, they are not as common or widespread as those caused by wind. Earthquakes can also generate waves in the ocean, known as tsunamis, but these are less frequent and have different characteristics than surface waves. Tides, on the other hand, are caused by the gravitational pull of the moon and sun and do not directly create surface waves.

75. Your Adjusted Maximum Dive Time (AMDT) can be best characterized as:

The maximum time you can dive at recreational limits

The maximum recommended time for a repetitive dive, taking into account Residual Nitrogen from previous dives

The longest dive you can complete without a decompression stop

Your actual dive time minus the 3 minute safety stop

The Adjusted Maximum Dive Time (AMDT) refers to the maximum recommended time for a repetitive dive, considering the Residual Nitrogen from previous dives. This means that it takes into account the nitrogen saturation in the diver's body and calculates the safe time for subsequent dives. It is important to consider this to avoid decompression sickness and ensure the safety of the diver.

Explanation

The Adjusted Maximum Dive Time (AMDT) refers to the maximum recommended time for a repetitive dive, considering the Residual Nitrogen from previous dives. This means that it takes into account the nitrogen saturation in the diver's body and calculates the safe time for subsequent dives. It is important to consider this to avoid decompression sickness and ensure the safety of the diver.

76. According to NAUI, a repetitive dive is any dive that occurs

Within 6 hours of your most recent dive

Within 12 hours of your most recent dive

Within 24 hours of your most recent dive

Since your arrival at the resort

A repetitive dive is defined by NAUI as any dive that occurs within 24 hours of your most recent dive. This means that if you have already gone diving within the past 24 hours, any subsequent dive within that time frame would be considered a repetitive dive.

Explanation

A repetitive dive is defined by NAUI as any dive that occurs within 24 hours of your most recent dive. This means that if you have already gone diving within the past 24 hours, any subsequent dive within that time frame would be considered a repetitive dive.

77. A diver enters the water for the first dive of the day. She spends 28 minutes at 77 feet. Her Letter Group is now ________.

A

B

E

G

After spending 28 minutes at 77 feet, the diver's Letter Group is now G. The Letter Group is a way to determine the amount of residual nitrogen in a diver's body after a dive. Each letter represents a different level of nitrogen saturation. As the diver descends and stays at a certain depth, nitrogen is absorbed into the body tissues. The longer the dive and the deeper the depth, the higher the nitrogen saturation. In this case, spending 28 minutes at 77 feet would result in a higher nitrogen saturation level, indicated by the letter G.

Explanation

After spending 28 minutes at 77 feet, the diver's Letter Group is now G. The Letter Group is a way to determine the amount of residual nitrogen in a diver's body after a dive. Each letter represents a different level of nitrogen saturation. As the diver descends and stays at a certain depth, nitrogen is absorbed into the body tissues. The longer the dive and the deeper the depth, the higher the nitrogen saturation. In this case, spending 28 minutes at 77 feet would result in a higher nitrogen saturation level, indicated by the letter G.

78. By law, SCUBA cylinders must be visually inspected ____________________ and hydrostatically tested _____________________.

Annually, every 3 years

Annually, every 5 years

With every air fill, annually

When dented, when showing visible signs of corrosion

SCUBA cylinders must be visually inspected annually to check for any visible signs of damage or corrosion. Additionally, they must undergo hydrostatic testing every 5 years to ensure their structural integrity and safety. This regular inspection and testing schedule is mandated by law to ensure that the cylinders are in proper working condition and do not pose any risks to divers.

Explanation

SCUBA cylinders must be visually inspected annually to check for any visible signs of damage or corrosion. Additionally, they must undergo hydrostatic testing every 5 years to ensure their structural integrity and safety. This regular inspection and testing schedule is mandated by law to ensure that the cylinders are in proper working condition and do not pose any risks to divers.

79. If you remove your 2nd stage regulator from your mouth while on a dive, you can resume breathing from the regulator after you:

Blast clear the water inside the regulator using air in your lungs

Purge the water inside the regulator using the purge button in the center of the regulator

Force the regulator to free-flow at depth to clear the water inside, then begin breathing normally

A or B above.

If you remove your 2nd stage regulator from your mouth while on a dive, you can resume breathing from the regulator after you blast clear the water inside the regulator using air in your lungs or purge the water inside the regulator using the purge button in the center of the regulator. Both options allow for the removal of water from the regulator, ensuring that it functions properly and can be used for breathing again.

Explanation

If you remove your 2nd stage regulator from your mouth while on a dive, you can resume breathing from the regulator after you blast clear the water inside the regulator using air in your lungs or purge the water inside the regulator using the purge button in the center of the regulator. Both options allow for the removal of water from the regulator, ensuring that it functions properly and can be used for breathing again.

80. An "overhead" dive is:

A dive where the diver's buddy swims above and behind the primary diver and breathes on his/her octopus regulator

A dive over a large school of fish

A dive with lots of extra equipment, or "overhead"

A specialized dive under ice or in a cave where the diver cannot readily surface

An "overhead" dive refers to a specialized dive that takes place under ice or in a cave where the diver is unable to easily reach the surface. This type of dive requires specific training and equipment due to the potential risks and challenges involved. The diver must navigate in confined spaces and rely on their equipment and skills to ensure a safe dive.

Explanation

An "overhead" dive refers to a specialized dive that takes place under ice or in a cave where the diver is unable to easily reach the surface. This type of dive requires specific training and equipment due to the potential risks and challenges involved. The diver must navigate in confined spaces and rely on their equipment and skills to ensure a safe dive.

81. It is difficult to determine the direction from which sounds originate underwater because:

Sound waves bounce off the bottom of the ocean and cancel each other out

Plankton and dissolved solids in the water mute the sounds making it hard to hear

Water is a poor medium for sound transmission, so sounds are more muffled

Water is a more efficient medium for sound transmission than air, meaning that sound waves travel faster through water. This can cause confusion in determining the direction from which sounds originate underwater because the sound waves reach our ears at different times, making it difficult to pinpoint the source of the sound accurately.

Explanation

Water is a more efficient medium for sound transmission than air, meaning that sound waves travel faster through water. This can cause confusion in determining the direction from which sounds originate underwater because the sound waves reach our ears at different times, making it difficult to pinpoint the source of the sound accurately.

82. Choice of a dive site should most importantly include assessment of several key conditions:

Beach erosion and offshore storms affecting the dive site

Water temperature and diver experience

Tides, wind direction/speed, wave height/period at the dive site

Available parking and toilets

When choosing a dive site, it is crucial to assess the tides, wind direction/speed, and wave height/period at the location. These factors directly impact the safety and comfort of the divers. Tides can affect the visibility and currents underwater, while wind direction/speed and wave height/period determine the surface conditions. By considering these conditions, divers can ensure a smooth and enjoyable dive experience. The other factors mentioned, such as beach erosion, offshore storms, water temperature, diver experience, available parking, and toilets, may also be important but are not as critical as the assessment of tides, wind, and waves.

Explanation

When choosing a dive site, it is crucial to assess the tides, wind direction/speed, and wave height/period at the location. These factors directly impact the safety and comfort of the divers. Tides can affect the visibility and currents underwater, while wind direction/speed and wave height/period determine the surface conditions. By considering these conditions, divers can ensure a smooth and enjoyable dive experience. The other factors mentioned, such as beach erosion, offshore storms, water temperature, diver experience, available parking, and toilets, may also be important but are not as critical as the assessment of tides, wind, and waves.

83. Assuming all other factors (such as equipment, wetsuit, etc) are the same, a diver that normally uses 18 pounds of lead in the ocean will need ______________ to dive in the lake.

Slightly more lead weight

Slightly less lead weight

The same amount of lead weight

A different type of weight because lead can't be used in fresh water

In the ocean, saltwater provides more buoyancy compared to freshwater in a lake. This means that a diver in a lake will experience less buoyancy and will need less weight to counteract it. Therefore, the diver will need slightly less lead weight in the lake compared to the ocean.

Explanation

In the ocean, saltwater provides more buoyancy compared to freshwater in a lake. This means that a diver in a lake will experience less buoyancy and will need less weight to counteract it. Therefore, the diver will need slightly less lead weight in the lake compared to the ocean.

84. A diver experiencing vertigo, or dizziness, is most likely an indication that:

The diver's ears are not equalized in balance

The diver is descending too quickly

The diver's head is too cold from chilly water "brain freeze"

The diver is diving too deep

When a diver experiences vertigo or dizziness, it is most likely an indication that their ears are not equalized in balance. Equalizing the pressure in the ears is crucial when diving, as the change in pressure underwater can cause discomfort and affect the diver's equilibrium. Failure to equalize the pressure can lead to symptoms like vertigo, as the imbalance affects the inner ear. This can be resolved by properly equalizing the pressure in the ears during the descent.

Explanation

When a diver experiences vertigo or dizziness, it is most likely an indication that their ears are not equalized in balance. Equalizing the pressure in the ears is crucial when diving, as the change in pressure underwater can cause discomfort and affect the diver's equilibrium. Failure to equalize the pressure can lead to symptoms like vertigo, as the imbalance affects the inner ear. This can be resolved by properly equalizing the pressure in the ears during the descent.

85. The primary factors determining your air consumption rate are:

Depth, Total Nitrogen Time, and fin size

Age, currents, and visibility

Water temperature, Residual Nitrogen Time, physical fitness of diver

Depth, physical activity, and water temperature

The primary factors that determine your air consumption rate while diving are depth, physical activity, and water temperature. Depth affects the pressure on your body, which in turn affects your breathing rate. Physical activity increases your breathing rate and therefore your air consumption. Water temperature also affects your breathing rate, as colder water can cause your body to work harder to maintain its temperature. These three factors combined have a significant impact on how quickly you consume air while diving.

Explanation

The primary factors that determine your air consumption rate while diving are depth, physical activity, and water temperature. Depth affects the pressure on your body, which in turn affects your breathing rate. Physical activity increases your breathing rate and therefore your air consumption. Water temperature also affects your breathing rate, as colder water can cause your body to work harder to maintain its temperature. These three factors combined have a significant impact on how quickly you consume air while diving.

86. The ____________ line is the reference line used on your compass to point the direction of travel

Lover

Lubber

Rubber

North arrow

The lubber line is the reference line used on your compass to point the direction of travel.

Explanation

The lubber line is the reference line used on your compass to point the direction of travel.

87. Hydrostatic testing SCUBA cylinders achieves which of these goals?

Checking the bottle for leaks

Testing for substandard metals that can corrode in water

Testing for metal fatigue that can cause the cylinder to fail under pressure

Checking the air inside the bottle for trace gasses that are harmful to humans, such as carbon monoxide

Hydrostatic testing of SCUBA cylinders is conducted to determine if there is any metal fatigue present in the cylinder that could lead to failure under pressure. This type of testing involves subjecting the cylinder to high pressure to evaluate its structural integrity. By doing so, any potential weaknesses or fatigue in the metal can be identified, ensuring the safety of the user.

Explanation

Hydrostatic testing of SCUBA cylinders is conducted to determine if there is any metal fatigue present in the cylinder that could lead to failure under pressure. This type of testing involves subjecting the cylinder to high pressure to evaluate its structural integrity. By doing so, any potential weaknesses or fatigue in the metal can be identified, ensuring the safety of the user.

88. Storing wet diving equipment in your car after a dive can_________________.

Expose the equipment to excessive temperature swings (freezing/heating) which is detrimental to the equipment

Can cause mildew to grow on the equipment, causing staining and foul odor

Promote corrosion in metal components, especially knife blades, clasps, and rings made of steel

All of the above

B & C above

Storing wet diving equipment in your car after a dive can expose the equipment to excessive temperature swings (freezing/heating), which is detrimental to the equipment. It can also cause mildew to grow on the equipment, leading to staining and foul odor. Additionally, it can promote corrosion in metal components, especially knife blades, clasps, and rings made of steel. Therefore, all of the above options are correct.

Explanation

Storing wet diving equipment in your car after a dive can expose the equipment to excessive temperature swings (freezing/heating), which is detrimental to the equipment. It can also cause mildew to grow on the equipment, leading to staining and foul odor. Additionally, it can promote corrosion in metal components, especially knife blades, clasps, and rings made of steel. Therefore, all of the above options are correct.

89. At a minimum, return to the dive boat or shore entry point with ______________ psi of air remaining in your cylinder.

100

250

500

1000

When scuba diving, it is important to always have enough air remaining in your cylinder to safely ascend to the surface. The recommended minimum amount of air to have left in your cylinder is 500 psi. This ensures that you have enough air to complete a controlled ascent and perform safety stops if necessary. Having this reserve of air also provides a margin of safety in case of any unexpected circumstances or emergencies that may arise during the dive.

Explanation

When scuba diving, it is important to always have enough air remaining in your cylinder to safely ascend to the surface. The recommended minimum amount of air to have left in your cylinder is 500 psi. This ensures that you have enough air to complete a controlled ascent and perform safety stops if necessary. Having this reserve of air also provides a margin of safety in case of any unexpected circumstances or emergencies that may arise during the dive.

90. One atmosphere of pressure is relative to the pressure exerted at a depth of ___________________ feet of water.

17.4

14.7

33

44.1

One atmosphere of pressure is equal to the pressure exerted at a depth of 33 feet of water. This is because the pressure exerted by a column of water increases with depth due to the weight of the water above it. At a depth of 33 feet, the weight of the water creates enough pressure to equal one atmosphere.

Explanation

One atmosphere of pressure is equal to the pressure exerted at a depth of 33 feet of water. This is because the pressure exerted by a column of water increases with depth due to the weight of the water above it. At a depth of 33 feet, the weight of the water creates enough pressure to equal one atmosphere.

91. NAUI recommends that divers observe a _____________ Surface Interval Time (SIT) between repetitive dives.

30 minute

1 hour

2 hour

4 hour

NAUI recommends that divers observe a 1-hour Surface Interval Time (SIT) between repetitive dives. This is important to allow the body to eliminate excess nitrogen absorbed during the previous dive and reduce the risk of decompression sickness. Taking a longer surface interval allows for better off-gassing of nitrogen, ensuring the safety of the diver. A shorter surface interval may not provide enough time for the body to adequately eliminate nitrogen, increasing the risk of decompression sickness.

Explanation

NAUI recommends that divers observe a 1-hour Surface Interval Time (SIT) between repetitive dives. This is important to allow the body to eliminate excess nitrogen absorbed during the previous dive and reduce the risk of decompression sickness. Taking a longer surface interval allows for better off-gassing of nitrogen, ensuring the safety of the diver. A shorter surface interval may not provide enough time for the body to adequately eliminate nitrogen, increasing the risk of decompression sickness.

92. A diver with an empty BCD and an aluminum cylinder is neutrally buoyant at depth with 15 pounds of lead.This diver could experience buoyancy problems towards the end of his or her dive because:

The aluminum tank becomes positively buoyant as it's air pressure decreases

15 pounds of lead on the surface only weighs 12.7 pounds under water

The aluminum tank becomes negatively buoyant as it's air pressure decreases

Residual nitrogen will build up in the diver's BCD

As the diver descends deeper, the pressure increases, causing the air inside the aluminum tank to compress. This compression reduces the volume of the air, making the tank less buoyant. However, as the diver ascends towards the end of the dive, the pressure decreases, causing the air inside the tank to expand. This expansion increases the volume of the air, making the tank more buoyant. Therefore, towards the end of the dive, the aluminum tank becomes positively buoyant as its air pressure decreases, which can cause buoyancy problems for the diver.

Explanation

As the diver descends deeper, the pressure increases, causing the air inside the aluminum tank to compress. This compression reduces the volume of the air, making the tank less buoyant. However, as the diver ascends towards the end of the dive, the pressure decreases, causing the air inside the tank to expand. This expansion increases the volume of the air, making the tank more buoyant. Therefore, towards the end of the dive, the aluminum tank becomes positively buoyant as its air pressure decreases, which can cause buoyancy problems for the diver.

93. Buildup of which gas in the body triggers the brain to signal our diaphragm and other muscles to breathe?

Carbon Monoxide

Carbon Dioxide

Nitrogen

Oxygen

When we breathe in oxygen, our body uses it to produce energy and releases carbon dioxide as a waste product. As we continue to breathe in oxygen, the levels of carbon dioxide in our body gradually increase. When the concentration of carbon dioxide in our blood reaches a certain threshold, it triggers the brain to send signals to our diaphragm and other muscles involved in breathing to contract and relax, causing us to breathe out the excess carbon dioxide and breathe in fresh oxygen. Therefore, the buildup of carbon dioxide in the body is what triggers the brain to signal our diaphragm and other muscles to breathe.

Explanation

When we breathe in oxygen, our body uses it to produce energy and releases carbon dioxide as a waste product. As we continue to breathe in oxygen, the levels of carbon dioxide in our body gradually increase. When the concentration of carbon dioxide in our blood reaches a certain threshold, it triggers the brain to send signals to our diaphragm and other muscles involved in breathing to contract and relax, causing us to breathe out the excess carbon dioxide and breathe in fresh oxygen. Therefore, the buildup of carbon dioxide in the body is what triggers the brain to signal our diaphragm and other muscles to breathe.

94. The absolute pressure exerted on a diver at 10 meters (33 feet) in sea water is:

64.4 psi

10 BAR

3 atmospheres of pressure

None of the above

not-available-via-ai

Explanation

not-available-via-ai

95. The "Lost Buddy Procedure" includes the following steps:

Ascend, look for your buddy's bubbles, if they are not present, continue to the agreed upon rendezvous point

Immediately ascend and look for your buddy at the surface

None of these

The correct answer is the "Lost Buddy Procedure" includes ascending a few feet, looking for your buddy's bubbles, ascending a few feet more, looking for bubbles, and repeating this process until surfaced, and then waiting at the surface for your buddy. This procedure is a safety measure in scuba diving to locate a lost buddy underwater. By ascending gradually and looking for bubbles, divers can increase the chances of finding their buddy and reuniting at the surface. Waiting at the surface ensures that both divers are safe and accounted for.

Explanation

The correct answer is the "Lost Buddy Procedure" includes ascending a few feet, looking for your buddy's bubbles, ascending a few feet more, looking for bubbles, and repeating this process until surfaced, and then waiting at the surface for your buddy. This procedure is a safety measure in scuba diving to locate a lost buddy underwater. By ascending gradually and looking for bubbles, divers can increase the chances of finding their buddy and reuniting at the surface. Waiting at the surface ensures that both divers are safe and accounted for.

96. Two divers enter the water with a New Letter Group of D, and plan to complete a 12 meter dive. Their new Residual Nitrogen Time will be _______ and their Adjusted Maximum Dive Time (AMDT) is _______ .

51, 29

49, 81

37, 93

93, 37

The correct answer is 37, 93. When divers enter the water with a New Letter Group of D, their Residual Nitrogen Time will be 37 minutes. This means that they must wait 37 minutes before they can safely ascend to the surface without risking decompression sickness. Their Adjusted Maximum Dive Time (AMDT) is 93 minutes, which is the maximum amount of time they can stay underwater without exceeding the no-decompression limits for that particular dive.

Explanation

The correct answer is 37, 93. When divers enter the water with a New Letter Group of D, their Residual Nitrogen Time will be 37 minutes. This means that they must wait 37 minutes before they can safely ascend to the surface without risking decompression sickness. Their Adjusted Maximum Dive Time (AMDT) is 93 minutes, which is the maximum amount of time they can stay underwater without exceeding the no-decompression limits for that particular dive.

97. A standard "adult" size scuba cylinder contains ________________ cubic feet of air and, (if measured at 1 BAR of pressure) is pressurized to __________________ PSI.

50, 5000

60, 2250

80, 3000

None of the above

A standard "adult" size scuba cylinder contains 80 cubic feet of air and, if measured at 1 BAR of pressure, is pressurized to 3000 PSI.

Explanation

A standard "adult" size scuba cylinder contains 80 cubic feet of air and, if measured at 1 BAR of pressure, is pressurized to 3000 PSI.

98. Your submersible pressure gauge is connected to your SCUBA cylinder via a __________________ in your first stage regulator.

High-pressure port

Second stage regulator

Low-pressure port

None of these

The correct answer is high-pressure port. A submersible pressure gauge is connected to a SCUBA cylinder via the high-pressure port in the first stage regulator. This port is designed to handle the high-pressure air coming from the cylinder and allows the pressure gauge to accurately measure the pressure inside the cylinder. The high-pressure port is typically located on the side or top of the first stage regulator and is specifically designed for this purpose. The second stage regulator is responsible for delivering air to the diver, not for connecting the pressure gauge. The low-pressure port is used for connecting other equipment, such as the second stage regulator or an alternate air source.

Explanation

The correct answer is high-pressure port. A submersible pressure gauge is connected to a SCUBA cylinder via the high-pressure port in the first stage regulator. This port is designed to handle the high-pressure air coming from the cylinder and allows the pressure gauge to accurately measure the pressure inside the cylinder. The high-pressure port is typically located on the side or top of the first stage regulator and is specifically designed for this purpose. The second stage regulator is responsible for delivering air to the diver, not for connecting the pressure gauge. The low-pressure port is used for connecting other equipment, such as the second stage regulator or an alternate air source.

99. Assume all dives require a 3 minute safety stop at 15 feet. The maximum dive time for a dive to 110 feet without an additional decompression stop is:

13 minutes

11 minutes

22 minutes

20 minutes

To calculate the maximum dive time without decompression stops, we subtract the time for descent, ascent, and the safety stop from the no-decompression limit (NDL). For a dive to 110 feet, the NDL is typically around 20 minutes. Subtracting time for descent (3 minutes), ascent (3 minutes), and the safety stop (3 minutes), the maximum dive time would be approximately 11 minutes.

Explanation

To calculate the maximum dive time without decompression stops, we subtract the time for descent, ascent, and the safety stop from the no-decompression limit (NDL). For a dive to 110 feet, the NDL is typically around 20 minutes. Subtracting time for descent (3 minutes), ascent (3 minutes), and the safety stop (3 minutes), the maximum dive time would be approximately 11 minutes.

100. The absolute pressure exerted by the Earth's atmosphere on a person standing on the shore at sea level is:

1 BAR

1 atmosphere of pressure

14.7 PSI

All of the above

The correct answer is "All of the above." This means that all the options listed - 1 atmosphere of pressure, 14.7 PSI, and 1 BAR - are correct and can be used to describe the absolute pressure exerted by the Earth's atmosphere on a person standing on the shore at sea level.

Explanation

The correct answer is "All of the above." This means that all the options listed - 1 atmosphere of pressure, 14.7 PSI, and 1 BAR - are correct and can be used to describe the absolute pressure exerted by the Earth's atmosphere on a person standing on the shore at sea level.

101. A burst disk prevents

Damage to the ear drum

An exploding scuba cylinder

A blown out mask lens

Overinflation of a BCD

A burst disk is a safety mechanism that is designed to relieve excess pressure in a scuba cylinder. If the pressure inside the cylinder exceeds a certain limit, the burst disk will rupture, allowing the excess pressure to escape. This prevents the cylinder from exploding, which could cause serious injury or even death to the diver. Therefore, the correct answer is that a burst disk prevents an exploding scuba cylinder.

Explanation

A burst disk is a safety mechanism that is designed to relieve excess pressure in a scuba cylinder. If the pressure inside the cylinder exceeds a certain limit, the burst disk will rupture, allowing the excess pressure to escape. This prevents the cylinder from exploding, which could cause serious injury or even death to the diver. Therefore, the correct answer is that a burst disk prevents an exploding scuba cylinder.

102. Four divers exit the water from a first dive with a Letter Group of I. The dive boat operator stipulates a 1 hour 30 minute Surface Interval Time (SIT) for all divers before the start of a second dive, to allow for lunch and travel time to a second dive site. The new dive site is an artificial reef at 45 feet. The Adjusted Maximum Dive Time for that repetitive dive is _____.

33 minutes

47 minutes

69 minutes

19 minutes

The correct answer is 33 minutes because the Adjusted Maximum Dive Time for a repetitive dive is calculated by subtracting the Surface Interval Time (SIT) from the No-Decompression Limit (NDL) of the dive site. In this case, the NDL for the artificial reef at 45 feet is 70 minutes. Subtracting the 1 hour 30 minute SIT from the NDL gives us 70 - 90 = -20 minutes. Since the result is negative, it means that the divers have exceeded their NDL and must reduce their dive time. The Adjusted Maximum Dive Time is therefore 0 minutes minus the excess time, which is 0 - (-20) = 20 minutes. However, the divers must always have a minimum of 10 minutes of surface time, so the final Adjusted Maximum Dive Time is 20 - 10 = 10 minutes. However, since this is a repetitive dive, the divers must also subtract 7 minutes from the Adjusted Maximum Dive Time, giving us a final result of 10 - 7 = 3 minutes. Therefore, the correct answer is 33 minutes.

Explanation

The correct answer is 33 minutes because the Adjusted Maximum Dive Time for a repetitive dive is calculated by subtracting the Surface Interval Time (SIT) from the No-Decompression Limit (NDL) of the dive site. In this case, the NDL for the artificial reef at 45 feet is 70 minutes. Subtracting the 1 hour 30 minute SIT from the NDL gives us 70 - 90 = -20 minutes. Since the result is negative, it means that the divers have exceeded their NDL and must reduce their dive time. The Adjusted Maximum Dive Time is therefore 0 minutes minus the excess time, which is 0 - (-20) = 20 minutes. However, the divers must always have a minimum of 10 minutes of surface time, so the final Adjusted Maximum Dive Time is 20 - 10 = 10 minutes. However, since this is a repetitive dive, the divers must also subtract 7 minutes from the Adjusted Maximum Dive Time, giving us a final result of 10 - 7 = 3 minutes. Therefore, the correct answer is 33 minutes.

103. Archimedes' Principle states that:

Gasses such as air are compressed by one atmosphere of pressure or 14.7 PSI for every 33 feet of depth

Water density is constant at all depths because water cannot be compressed

None of these

The given answer is correct because Archimedes' Principle states that the upward buoyant force experienced by an object immersed in a fluid is equal to the weight of the fluid that is displaced by the object. This means that the buoyant force is directly proportional to the weight of the fluid displaced, which in turn is equal to the weight of the object itself. This principle helps explain why objects float or sink in fluids based on their density relative to the density of the fluid.

Explanation

The given answer is correct because Archimedes' Principle states that the upward buoyant force experienced by an object immersed in a fluid is equal to the weight of the fluid that is displaced by the object. This means that the buoyant force is directly proportional to the weight of the fluid displaced, which in turn is equal to the weight of the object itself. This principle helps explain why objects float or sink in fluids based on their density relative to the density of the fluid.

104. NAUI recommends that all divers perform a "safety stop" at 10 meters (33 feet) during ascent.

True

False

NAUI does not recommend that all divers perform a "safety stop" at 10 meters (33 feet) during ascent. A safety stop is typically performed at a depth of 3-5 meters (10-15 feet) for a duration of 3 minutes to allow for off-gassing and to reduce the risk of decompression sickness. The depth and duration of a safety stop may vary depending on the dive profile and the diver's certification level, but it is generally not recommended to perform a safety stop at 10 meters (33 feet).

Explanation

NAUI does not recommend that all divers perform a "safety stop" at 10 meters (33 feet) during ascent. A safety stop is typically performed at a depth of 3-5 meters (10-15 feet) for a duration of 3 minutes to allow for off-gassing and to reduce the risk of decompression sickness. The depth and duration of a safety stop may vary depending on the dive profile and the diver's certification level, but it is generally not recommended to perform a safety stop at 10 meters (33 feet).

105. When using NAUI dive tables, any dive up to and including 40' is considered a _______________ dive.

No-decompression

Shallow

Limited

Standard

A "no-decompression" dive means that a diver can ascend to the surface without needing to make decompression stops during the ascent. It's applicable for dives up to a certain depth where the risk of decompression sickness is minimal.

Explanation

A "no-decompression" dive means that a diver can ascend to the surface without needing to make decompression stops during the ascent. It's applicable for dives up to a certain depth where the risk of decompression sickness is minimal.

106. Water cools exposed skin at a rate ____________ than air.

10 times faster

25 times slower

25 times faster

50 times faster

Water cools exposed skin at a rate 25 times faster than air because water has a higher thermal conductivity compared to air. This means that heat is transferred more efficiently from the skin to the water, resulting in a faster cooling effect. Additionally, water has a higher specific heat capacity, meaning it can absorb more heat energy before its temperature rises significantly. This combination of higher thermal conductivity and specific heat capacity makes water a more effective coolant for the skin compared to air.

Explanation

Water cools exposed skin at a rate 25 times faster than air because water has a higher thermal conductivity compared to air. This means that heat is transferred more efficiently from the skin to the water, resulting in a faster cooling effect. Additionally, water has a higher specific heat capacity, meaning it can absorb more heat energy before its temperature rises significantly. This combination of higher thermal conductivity and specific heat capacity makes water a more effective coolant for the skin compared to air.

107. A regulator free flow happens when the diaphragm inside your regulator gets stuck in the open position. You can best stop a regulator free flow at the surface by ___________________________ and at depth by ___________________________.

Turning off your air at the cylinder, putting your regulator inside your wetsuit

Placing your fingers or thumb over the mouthpiece, turning the regulator so the mouthpiece points down

Turning the regulator so the mouthpiece points down, putting the regulator in your mouth and blowing hard

None of the above.

To stop a regulator free flow at the surface, you should place your fingers or thumb over the mouthpiece and turn the regulator so the mouthpiece points down. This action helps to restrict the airflow and prevent the free flow. At depth, the same technique can be used to stop the free flow. This is because placing your fingers or thumb over the mouthpiece restricts the airflow and reduces the chance of the diaphragm getting stuck in the open position.

Explanation

To stop a regulator free flow at the surface, you should place your fingers or thumb over the mouthpiece and turn the regulator so the mouthpiece points down. This action helps to restrict the airflow and prevent the free flow. At depth, the same technique can be used to stop the free flow. This is because placing your fingers or thumb over the mouthpiece restricts the airflow and reduces the chance of the diaphragm getting stuck in the open position.

108. Key reasons to wear an exposure suit include:

Keep your body warm in colder water

Prevent sunburn

Protect from scrapes and stings

Only A & C above

A, B & C above

An exposure suit is worn to keep the body warm in colder water, prevent sunburn, and protect from scrapes and stings. Wearing an exposure suit helps to maintain body temperature in cold water by providing insulation. It also acts as a barrier against harmful UV rays from the sun, preventing sunburn. Additionally, exposure suits are designed to protect the skin from scrapes and stings that may be encountered while diving or swimming in various environments. Therefore, the correct answer is A, B & C above.

Explanation

An exposure suit is worn to keep the body warm in colder water, prevent sunburn, and protect from scrapes and stings. Wearing an exposure suit helps to maintain body temperature in cold water by providing insulation. It also acts as a barrier against harmful UV rays from the sun, preventing sunburn. Additionally, exposure suits are designed to protect the skin from scrapes and stings that may be encountered while diving or swimming in various environments. Therefore, the correct answer is A, B & C above.

109. A typical three-gauge console consists of:

A compass, a submersible pressure gauge, and a depth gauge

A watch, a flashlight, and waterproof dive tables

A compass, pressure gauge, and a dive computer

A or C above

None of the above

A typical three-gauge console consists of a compass, a submersible pressure gauge, and a depth gauge. However, it can also consist of a compass, pressure gauge, and a dive computer. Both options A and C include a compass and a pressure gauge, making them the correct answers.

Explanation

A typical three-gauge console consists of a compass, a submersible pressure gauge, and a depth gauge. However, it can also consist of a compass, pressure gauge, and a dive computer. Both options A and C include a compass and a pressure gauge, making them the correct answers.

110. Enriched Air Nitrox (EANx) or "Nitrox" is a blended gas consisting of:

Lightly lower levels of both oxygen and nitrogen and more trace gasses

Pure oxygen with no nitrogen or trace gasses

Slightly lower levels of oxygen and higher levels of nitrogen

Slightly lower levels of nitrogen and higher levels of oxygen

Enriched Air Nitrox (EANx) or "Nitrox" is a gas blend used in diving that contains slightly lower levels of nitrogen and higher levels of oxygen compared to regular air. This gas mixture is used to reduce the risk of decompression sickness in divers by decreasing the amount of nitrogen absorbed by the body during a dive. By having lower levels of nitrogen, divers can extend their bottom time and decrease their surface interval between dives. The higher levels of oxygen also provide additional benefits, such as reducing fatigue and allowing for faster off-gassing of nitrogen.

Explanation

Enriched Air Nitrox (EANx) or "Nitrox" is a gas blend used in diving that contains slightly lower levels of nitrogen and higher levels of oxygen compared to regular air. This gas mixture is used to reduce the risk of decompression sickness in divers by decreasing the amount of nitrogen absorbed by the body during a dive. By having lower levels of nitrogen, divers can extend their bottom time and decrease their surface interval between dives. The higher levels of oxygen also provide additional benefits, such as reducing fatigue and allowing for faster off-gassing of nitrogen.

111. The method of donning your fins using your buddy for stability at the shore or on the dive boat is called:

The "Do-si-do"

The "Sweep"

The "Figure four"

"The Buddy Method"

The correct answer is "The Buddy Method". The "Figure four" is not a method of donning fins, but rather a term used to describe a specific leg position. The "Do-si-do" is a term used in square dancing and is not related to donning fins. The "Sweep" is also not a method of donning fins. The Buddy Method involves using your buddy for stability while donning your fins, either at the shore or on the dive boat.

Explanation

The correct answer is "The Buddy Method". The "Figure four" is not a method of donning fins, but rather a term used to describe a specific leg position. The "Do-si-do" is a term used in square dancing and is not related to donning fins. The "Sweep" is also not a method of donning fins. The Buddy Method involves using your buddy for stability while donning your fins, either at the shore or on the dive boat.

112. Your best source of assistance as a diver will come from:

Your dive computer

Your submersible pressure gauge

Your buddy

Your NAUI classroom and practical training

Your buddy is the best source of assistance as a diver because they are trained to respond to emergencies and can provide immediate help if needed. They can assist with equipment malfunctions, guide you back to the surface in case of disorientation, and provide support in case of an emergency situation. Having a reliable buddy is essential for safety and ensures that someone is always there to help and watch out for each other during a dive.

Explanation

Your buddy is the best source of assistance as a diver because they are trained to respond to emergencies and can provide immediate help if needed. They can assist with equipment malfunctions, guide you back to the surface in case of disorientation, and provide support in case of an emergency situation. Having a reliable buddy is essential for safety and ensures that someone is always there to help and watch out for each other during a dive.

113. Saturation diving is ___________________.

When divers' lungs are saturated with a viscous, highly oxygenated fluid

Diving in a specialized saturation suit which keeps the body warm during winter diving.

None of these

Saturation diving involves spending an extended period of time living in a pressurized cylinder and breathing specialized gases. This is necessary for working in very deep water conditions. The pressurized environment helps prevent decompression sickness, and the specialized gases are used to maintain the proper oxygen levels for the divers. This method allows divers to work at great depths for longer periods without needing to constantly ascend and descend, increasing efficiency and safety.

Explanation

Saturation diving involves spending an extended period of time living in a pressurized cylinder and breathing specialized gases. This is necessary for working in very deep water conditions. The pressurized environment helps prevent decompression sickness, and the specialized gases are used to maintain the proper oxygen levels for the divers. This method allows divers to work at great depths for longer periods without needing to constantly ascend and descend, increasing efficiency and safety.

114. A group of divers complete a 20-minute dive and have a Residual Nitrogen Time of 37 minutes from a previous dive. Their Total Nitrogen Time is _______________.

17 minutes

20 minutes

57 minutes

Impossible to calculate from the information given.

The Total Nitrogen Time is 57 minutes.

To calculate the Total Nitrogen Time, you simply add the Residual Nitrogen Time from the previous dive to the current dive time:

Total Nitrogen Time = Previous Residual Nitrogen Time + Current Dive Time Total Nitrogen Time = 37 minutes + 20 minutes Total Nitrogen Time = 57 minutes

Explanation

The Total Nitrogen Time is 57 minutes.

To calculate the Total Nitrogen Time, you simply add the Residual Nitrogen Time from the previous dive to the current dive time:

Total Nitrogen Time = Previous Residual Nitrogen Time + Current Dive Time Total Nitrogen Time = 37 minutes + 20 minutes Total Nitrogen Time = 57 minutes

115. After successfully completing the classroom and confined water portion of a certification class, to become a NAUI-certified SCUBA diver, you must complete ________________ open water dives, with an instructor in the ocean or in a lake.

3

5

7

10

To become a NAUI-certified SCUBA diver, after completing the classroom and confined water portion of the certification class, you are required to complete 5 open water dives with an instructor in the ocean or in a lake. These open water dives provide you with the opportunity to apply the knowledge and skills learned in the classroom and confined water sessions in a real-world diving environment. It allows you to gain practical experience and build confidence in your diving abilities under the guidance and supervision of an instructor.

Explanation

To become a NAUI-certified SCUBA diver, after completing the classroom and confined water portion of the certification class, you are required to complete 5 open water dives with an instructor in the ocean or in a lake. These open water dives provide you with the opportunity to apply the knowledge and skills learned in the classroom and confined water sessions in a real-world diving environment. It allows you to gain practical experience and build confidence in your diving abilities under the guidance and supervision of an instructor.

116. Markings stamped on the side of a SCUBA cylinder include (check all that apply)

Cylinder capacity in volume and pressure

Boot style

Serial number

Color

Manufacturer

Regulator type (standard or high-performance)

Yoke circumference

Date of previous hydrostatic test(s)

O-Ring specifications

The markings stamped on the side of a SCUBA cylinder include the serial number, date of previous hydrostatic test(s), cylinder capacity in volume and pressure, and manufacturer. These markings are important for identification and safety purposes. The serial number helps track the cylinder and ensure it is properly maintained. The date of previous hydrostatic test(s) indicates when the cylinder was last tested for safety. The cylinder capacity in volume and pressure is important for determining the amount of air it can hold and the maximum pressure it can withstand. The manufacturer's marking provides information about the origin and quality of the cylinder.

Explanation

The markings stamped on the side of a SCUBA cylinder include the serial number, date of previous hydrostatic test(s), cylinder capacity in volume and pressure, and manufacturer. These markings are important for identification and safety purposes. The serial number helps track the cylinder and ensure it is properly maintained. The date of previous hydrostatic test(s) indicates when the cylinder was last tested for safety. The cylinder capacity in volume and pressure is important for determining the amount of air it can hold and the maximum pressure it can withstand. The manufacturer's marking provides information about the origin and quality of the cylinder.

Submit

117. A steel SCUBA cylinder is roughly neutrally buoyant when full of air and positively buoyant when close to empty.

True

False

A steel SCUBA cylinder is not neutrally buoyant when full of air. It is actually positively buoyant when full of air because the air inside the cylinder adds buoyancy. As the air is consumed and the cylinder becomes empty, it becomes less buoyant and eventually sinks. Therefore, the correct answer is false.

Explanation

A steel SCUBA cylinder is not neutrally buoyant when full of air. It is actually positively buoyant when full of air because the air inside the cylinder adds buoyancy. As the air is consumed and the cylinder becomes empty, it becomes less buoyant and eventually sinks. Therefore, the correct answer is false.

118. There are several distinct styles of buoyancy compensating devices (BCDs), including:

Jacket/vest

Horse collar

Back/rear flotation

Diving bell

A and C above

A, B & C above

A, B, C & D above

The correct answer is A, B & C above. This means that there are several distinct styles of buoyancy compensating devices (BCDs) which include the jacket/vest, horse collar, and back/rear flotation. The answer excludes the option of diving bell, as it is not considered a style of BCD.

Explanation

The correct answer is A, B & C above. This means that there are several distinct styles of buoyancy compensating devices (BCDs) which include the jacket/vest, horse collar, and back/rear flotation. The answer excludes the option of diving bell, as it is not considered a style of BCD.

119. You are recovering an unresponsive diver from the bottom. His BCD becomes over-inflated and his ascent becomes rapid and uncontrolled. You should:

Let him go, ascend at a safe rate, and resume the rescue at the surface

Hold on to him and ascend at the same rate

Deflate your BCD and use your weight to try to drag him back to neutral buoyancy

None of the above

When a diver becomes unresponsive and their BCD becomes over-inflated, it can cause a rapid and uncontrolled ascent. Holding on to the diver and ascending at the same rate can put both the rescuer and the diver at risk. Deflating the rescuer's BCD and using their weight to try to drag the diver back to neutral buoyancy may not be effective in this situation. The safest option is to let go of the diver, ascend at a safe rate, and resume the rescue at the surface where proper assistance can be provided.

Explanation

When a diver becomes unresponsive and their BCD becomes over-inflated, it can cause a rapid and uncontrolled ascent. Holding on to the diver and ascending at the same rate can put both the rescuer and the diver at risk. Deflating the rescuer's BCD and using their weight to try to drag the diver back to neutral buoyancy may not be effective in this situation. The safest option is to let go of the diver, ascend at a safe rate, and resume the rescue at the surface where proper assistance can be provided.

120. Contingency SCUBA can be characterized by:

Letting your buddy breathe off your octo/backup 2nd stage regulator if he/she runs out of air

Planning your dive with your buddy and discussing what to do in the case of emergency

Telling your friends and family where you will be diving in case of an accident

Bringing a completely independent SCUBA cylinder and regulator on your dive

Contingency SCUBA can be characterized by bringing a completely independent SCUBA cylinder and regulator on your dive. This means having a separate set of equipment that is not connected to your buddy's equipment. This is important because it provides an additional source of air in case of an emergency, such as your buddy running out of air or equipment failure. By having a completely independent system, you can ensure that you have a backup option to safely complete your dive.

Explanation

Contingency SCUBA can be characterized by bringing a completely independent SCUBA cylinder and regulator on your dive. This means having a separate set of equipment that is not connected to your buddy's equipment. This is important because it provides an additional source of air in case of an emergency, such as your buddy running out of air or equipment failure. By having a completely independent system, you can ensure that you have a backup option to safely complete your dive.

121. The top five gasses found in normal (atmospheric) air by volume are:

Nitrogen, Oxygen, Carbon Monoxide, Hydrogen, Helium

Carbon Monoxide, Nitrogen, Oxygen, Xenon, Water Vapor

Nitrogen, Oxygen, Argon, Carbon Dioxide, Neon

Oxygen, Nitrogen, Carbon Dioxide, Helium, Radon

The correct answer is Nitrogen, Oxygen, Argon, Carbon Dioxide, Neon. These five gases are found in normal atmospheric air in varying volumes. Nitrogen is the most abundant gas, making up about 78% of the air. Oxygen is the second most abundant gas, comprising about 21%. Argon is present in trace amounts, around 0.93%. Carbon Dioxide is a greenhouse gas and is present in very small amounts, around 0.04%. Neon is an inert gas and is found in even smaller quantities.

Explanation

The correct answer is Nitrogen, Oxygen, Argon, Carbon Dioxide, Neon. These five gases are found in normal atmospheric air in varying volumes. Nitrogen is the most abundant gas, making up about 78% of the air. Oxygen is the second most abundant gas, comprising about 21%. Argon is present in trace amounts, around 0.93%. Carbon Dioxide is a greenhouse gas and is present in very small amounts, around 0.04%. Neon is an inert gas and is found in even smaller quantities.

122. Two divers enjoy a 40 minute dive at 27 meters (90 feet). The divers are required to make a decompression stop at 5 meters (15 feet) for _________ minutes.

3 minutes

5 minutes

7 minutes

18 minutes

This is not allowed by NAUI dive tables

The divers are required to make a decompression stop at 5 meters (15 feet) for 7 minutes. This is because when diving at depths greater than 10 meters (33 feet), the body absorbs nitrogen from the air. If the divers ascend too quickly, the nitrogen can form bubbles in the bloodstream, causing decompression sickness. The purpose of the decompression stop is to allow the body to gradually release the absorbed nitrogen and prevent decompression sickness. The duration of the stop is determined by dive tables, which outline the recommended decompression times based on the depth and duration of the dive. In this case, the dive tables recommend a 7-minute stop at 5 meters (15 feet) to ensure a safe ascent.

Explanation

The divers are required to make a decompression stop at 5 meters (15 feet) for 7 minutes. This is because when diving at depths greater than 10 meters (33 feet), the body absorbs nitrogen from the air. If the divers ascend too quickly, the nitrogen can form bubbles in the bloodstream, causing decompression sickness. The purpose of the decompression stop is to allow the body to gradually release the absorbed nitrogen and prevent decompression sickness. The duration of the stop is determined by dive tables, which outline the recommended decompression times based on the depth and duration of the dive. In this case, the dive tables recommend a 7-minute stop at 5 meters (15 feet) to ensure a safe ascent.

123. When clearing water from inside a mask fitted with a purge valve, the diver should:

Ascend and drain the mask of water at the surface

Any of the above will work

The correct answer is to look down, hold the top of the mask to the forehead, and exhale through the nose until the water is cleared. This method allows the water to flow out of the mask through the purge valve, which is located at the bottom of the mask. By looking down, the diver ensures that the water will flow out of the mask and not back into it. Holding the top of the mask to the forehead helps create a seal and prevents water from entering the mask. Exhaling through the nose helps to clear any remaining water from the mask.

Explanation

The correct answer is to look down, hold the top of the mask to the forehead, and exhale through the nose until the water is cleared. This method allows the water to flow out of the mask through the purge valve, which is located at the bottom of the mask. By looking down, the diver ensures that the water will flow out of the mask and not back into it. Holding the top of the mask to the forehead helps create a seal and prevents water from entering the mask. Exhaling through the nose helps to clear any remaining water from the mask.

124. The diver can become dehydrated while diving because:

Air in the scuba cylinder has had moisture removed

Salt water causes the diver to lose water through his/her skin

Drysuit undergarments cause excessive persperation

All of the above

The correct answer is "Air in the scuba cylinder has had moisture removed." When divers breathe from a scuba cylinder, the air they inhale is dry because the moisture has been removed. Breathing dry air for an extended period can lead to dehydration. The other options mentioned, such as salt water causing water loss through the skin and drysuit undergarments causing excessive perspiration, may contribute to fluid loss but are not the primary cause of dehydration while diving.

Explanation

The correct answer is "Air in the scuba cylinder has had moisture removed." When divers breathe from a scuba cylinder, the air they inhale is dry because the moisture has been removed. Breathing dry air for an extended period can lead to dehydration. The other options mentioned, such as salt water causing water loss through the skin and drysuit undergarments causing excessive perspiration, may contribute to fluid loss but are not the primary cause of dehydration while diving.

125. Of these options, check off all the parts of your body with air cavities most likely impacted by changes in pressure while diving:

Stomach

Ears

Heart

Lungs

Bone marrow

Blood vessels

Sinuses

Teeth

Joints

The correct answer is ears, lungs, and sinuses. These three body parts have air cavities that are most likely impacted by changes in pressure while diving. The ears can experience pressure changes that can cause discomfort or even damage to the eardrums. The lungs can also be affected by pressure changes, especially during ascent and descent, which can lead to lung overexpansion injuries. The sinuses can become congested or experience pain due to pressure changes. The other body parts listed do not have air cavities and are not directly impacted by pressure changes while diving.

Explanation

The correct answer is ears, lungs, and sinuses. These three body parts have air cavities that are most likely impacted by changes in pressure while diving. The ears can experience pressure changes that can cause discomfort or even damage to the eardrums. The lungs can also be affected by pressure changes, especially during ascent and descent, which can lead to lung overexpansion injuries. The sinuses can become congested or experience pain due to pressure changes. The other body parts listed do not have air cavities and are not directly impacted by pressure changes while diving.

Submit

126. When performing a ladder exit, you must always (check all that apply)

Avoid the ladder zone if another diver is on or near the ladder

Look for alternate boats or shore exits in case the boat becomes disabled

Avoid clinging to the ladder to remove fins or adjust equipment

Place both feet firmly on each rung when ascending the ladder

Remove your mask and regulator so you can see better and communicate with the boat staff

When performing a ladder exit, it is important to avoid the ladder zone if another diver is on or near the ladder to prevent any collisions or accidents. Clinging to the ladder to remove fins or adjust equipment should also be avoided as it can cause instability and potentially lead to falls. It is crucial to place both feet firmly on each rung when ascending the ladder to ensure a safe and stable climb.

Explanation

When performing a ladder exit, it is important to avoid the ladder zone if another diver is on or near the ladder to prevent any collisions or accidents. Clinging to the ladder to remove fins or adjust equipment should also be avoided as it can cause instability and potentially lead to falls. It is crucial to place both feet firmly on each rung when ascending the ladder to ensure a safe and stable climb.

Submit

127. When entering the water for a shore dive from a beach with low rolling waves, you should:

Time the waves to determine their height and period

Quickly swim out through the surf zone and into deeper water away from the beach

Swim sideways along the beach to avoid rip currents

A & C Above

When entering the water for a shore dive from a beach with low rolling waves, it is important to quickly swim out through the surf zone and into deeper water away from the beach. This is because the surf zone is the area where the waves are breaking, and swimming through it can be difficult and potentially dangerous. By swimming out quickly, divers can avoid getting caught in the breaking waves and reach calmer waters where they can start their dive more safely. Swimming sideways along the beach to avoid rip currents may also be a good strategy, but it is not mentioned in the question, so it cannot be considered as part of the correct answer.

Explanation

When entering the water for a shore dive from a beach with low rolling waves, it is important to quickly swim out through the surf zone and into deeper water away from the beach. This is because the surf zone is the area where the waves are breaking, and swimming through it can be difficult and potentially dangerous. By swimming out quickly, divers can avoid getting caught in the breaking waves and reach calmer waters where they can start their dive more safely. Swimming sideways along the beach to avoid rip currents may also be a good strategy, but it is not mentioned in the question, so it cannot be considered as part of the correct answer.

128. The primary benefit of using nitrox gas, also called Enriched Air Nitrox (EANx) while diving include:

Less time at each decompression stop

Slower air consumption rate

Increased bottom time at deep depths

Decreased risk from air embolism, pneumothorax, or other pulmonary medical conditions

None of the above

Using nitrox gas, also known as Enriched Air Nitrox (EANx), while diving can provide the primary benefit of less time at each decompression stop. Nitrox gas has a higher oxygen content compared to regular air, which allows divers to stay at depth for longer periods without accumulating as much nitrogen in their body tissues. This reduces the need for lengthy decompression stops during ascent, as there is less nitrogen to off-gas. Consequently, divers using nitrox can enjoy extended bottom times and shorter surface intervals between dives. The other options listed do not accurately describe the primary benefit of using nitrox gas.

Explanation

Using nitrox gas, also known as Enriched Air Nitrox (EANx), while diving can provide the primary benefit of less time at each decompression stop. Nitrox gas has a higher oxygen content compared to regular air, which allows divers to stay at depth for longer periods without accumulating as much nitrogen in their body tissues. This reduces the need for lengthy decompression stops during ascent, as there is less nitrogen to off-gas. Consequently, divers using nitrox can enjoy extended bottom times and shorter surface intervals between dives. The other options listed do not accurately describe the primary benefit of using nitrox gas.

129. The benefits of a weight-integrated BCD include (check all that apply)

Comfort, since the weights are not strapped to the body

The diver is more streamlined in the water

The diver is able to descend to depth more quickly

The ability to easily ditch weights if needed

They are more expensive and communicate to others you are an experienced diver

Weight-integrated BCDs allow divers to easily ditch weights if necessary, which can be crucial in emergency situations. Additionally, these BCDs provide comfort as the weights are not strapped directly to the body, allowing for more freedom of movement.

Explanation

Weight-integrated BCDs allow divers to easily ditch weights if necessary, which can be crucial in emergency situations. Additionally, these BCDs provide comfort as the weights are not strapped directly to the body, allowing for more freedom of movement.

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130. Which of these are additional certifications that a NAUI certified diver may pursue beyond the basic Open Water Certification? (Check all that apply)

Advanced Diver

Enriched Air Nitrox (EANx) Diver

SNUBA

Training Assistant

Underwater Volcano Diver

Fresh Water Diver

Dry Suit Diver

Underwater Photography

Rescue Diver

Undersea Watercraft Diver

A NAUI certified diver may pursue the Advanced Diver certification to further enhance their diving skills and knowledge. The Enriched Air Nitrox (EANx) Diver certification allows divers to safely dive with higher levels of oxygen in their breathing gas, extending their bottom time. The Training Assistant certification enables divers to assist in teaching diving courses. The Dry Suit Diver certification is for divers who want to learn how to properly dive with a dry suit, which provides insulation in cold water. Underwater Photography certification is for divers interested in capturing underwater images. The Rescue Diver certification is for divers who want to learn how to respond to diving emergencies and assist in rescue situations.

Explanation

A NAUI certified diver may pursue the Advanced Diver certification to further enhance their diving skills and knowledge. The Enriched Air Nitrox (EANx) Diver certification allows divers to safely dive with higher levels of oxygen in their breathing gas, extending their bottom time. The Training Assistant certification enables divers to assist in teaching diving courses. The Dry Suit Diver certification is for divers who want to learn how to properly dive with a dry suit, which provides insulation in cold water. Underwater Photography certification is for divers interested in capturing underwater images. The Rescue Diver certification is for divers who want to learn how to respond to diving emergencies and assist in rescue situations.

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