Head The toilet on a boat. Bareboats usually have between 1 and 4 heads. Some are shared and some are ensuites to the cabins. They have very thin pipes, and use a macerator to break down waste into small pieces, so it's very important not to put any foreign matter in them. The system can be opened or closed, with waste stored in a holding tank on board until the boat is in an area where emptying is permitted. The loo on a boat in the Whitsundays is probably the loo with the b