To explore America.
To make sure the Earth was round.
To explore a western route to East Asia/the Indies.
To find pirates.
Water travel is easier than land travel.
The Ottoman Turks had made land travel to the Far East dangerous.
To convert East Asians to Catholicism.
Gold would be easier to ship on a boat.
Because an eastern sea route was reached around Africa's southern tip.
The king's advisers felt that Columbus had underestimated the distance of a western journey to Asia.
The king was Catholic and thought the Earth was flat.
A and B
The Santa Maria
During his first trip.
During his second trip.
After his last trip.
Until he died, he thought he had explored Asia.