+2 food on water tiles.
Ships large enough to carry the 50 to 100 people needed to found a colony along with all the supplies and food necessary to keep those colonists alive could not make landfall just anywhere. Because of the significant depth of their keels, such ships had to either carry all their contents in smaller row boats or search for a natural harbor, a portion of coast where the water adjacent the land was deep. Building a dock, a long wooden walkway stretching into the sea, could allow ships to make landfall in areas that lacked a natural harbor. Soon the east coast of the Americas was littered with docks as more and more massive ships arrived carrying their colonial cargos.