Which three explorers made their journeys almost exclusively by water?

Christopher columbus, James cook,  Ferdinand Magellan.

Explanation:

The explorers made their journeys through the water exclusively and made their discoveries and explorations of new lands as the Columbus discovered North America and then went on to the Caribbean, Central America, and South America and found the new world. James Cook was a British explorer, navigator, and cartographer who made voyages in the pacific ocean and then the eastern coastline of Australia and also founded the Hawaiian islands. Magellan was a Portuguese explorer who organized Spanish exploration of the eastern coast of indies.  Resulting in the first circumnavigation of the earth. Name the pacific ocean as the peaceful sea and thus his name is given to the Magellan Strait.

6, 4, 5, 1 are true. the others are false.