As long as there have been sailors, thereBs been the need for them to Cgo to the bathroom.D Of course it wasnBt called that on the ships before or after the time of Columbus. In the early days of sail, when ships first ventured out of the sight of their own lands, they called it many things, mostly vulgar things, but it all meant the same thing.
Naval ships today use seawater, or brine, for flushing real toilets that are located liberally throughout the ships. Sailors no longer have to go to the bow and hang themselves over open water to take care of business. Waste on naval ships is held in tanks until the vessel is well out to sea, at which time it is disintegrated in a special treatment plant aboard, and discharged overboard.
But such discharges anywhere near the shores of the United States are highly illegal. Pleasure boats are required to have Cholding tanksD on board, and marinas are required to provide Cpumping outD services F most provide them free F which sends the waste into the local sewer or septic systems, thus saving inland and coastal waters from further pollution.
Despite these modern ways of doing what sailors have always done, and despite the passage of hundreds of years, the toilet on board is still Cthe head,D and Cthe headD it will always be.