Hammocks woven from hammok tree fibers were a bit rough and uncomfortable, so some tribes started using softer material like the sisal plant, or even sheets of cotton. By the seventeenth century many European countries were utilizing the hammock as standard issue in their growing navies. Before hammocks, sailors used to simply lie down and sleep on the deck of the ship. During a storm this was incredibly uncomfortable and dangerous. Hammocks however, moved in rhythm with the ship and their design made it improbable that anyone would fall out. They could also be taken down and stowed away when not in use. Sailors in fact, liked them so much that they often took their hammock with them when they went ashore. This in turn led to the growing popularity of hammocks among non-sailors and ...