Why did it used to be harder to sail over deep ocean, compared to shallow waters

Question

Why did it used to be harder to sail over deep ocean, compared to shallow waters

In: 152

Answer 1

it also has to do with tools of the trade. sailors could always figure out their latitude fairly easily, but calculating their longitude wasn’t available to anyone until the late 18th century. so the idea of crossing into the unknown was a very daunting task.