A
boatswain (, formerly and dialectally also ),
bo's'n,
bos'n, or
bosun, is the senior crewman of the
deck department and is responsible for the components of a ship's
hull. The boatswain supervises the other members of the ship's deck department, and typically is not a
watchstander, except on vessels with small crews. Other duties vary depending on the type of ship, her crewing, and other factors.