Head (watercraft)
From Wikipedia, the free encyclopedia
The head (or heads) is a ship's water closet or toilet.
The term derives from sailing ships in which the toilet area for the regular sailors was placed at the head or bow of the ship. In sailing ships this position was sensible for two reasons: first, it was down-wind, since the prevailing winds came from the stern of the ship; secondly, if placed somewhat above the water line, vents or slots cut near the floor level would allow normal wave action to wash out the facility. Only the captain had his private toilet near his quarters, below the coincidentally-named poop deck.
In many modern boats, the heads look similar to a seated, land-type toilet, but have several technical differences. Rather than using a cistern and gravity to flush the waste away through a plumbing trap to a drain, there is a system of valves and pumps that brings sea water into the toilet and pumps the waste out through the hull. In small boats the pump is often hand operated. The cleaning mechanism is often easily blocked if too much toilet paper or other fibrous material is put down the pan.