A boatswain or bosun /ˈbo.sn̩/ is an unlicensed member of the deck department of a merchant ship. The boatswain supervises the other unlicensed members of the ship's deck department, and typically not a watchstander, except on vessels with small crews. Other duties vary depending on the type of ship, its crewing, and other factors. Etymology The word boatswain has been in the English language since approximately 1450. It is derived from late Old English batswegen, from bat ("boat"… (More on Boatswain)