Boatswain

Boatswain
The boatswain aboard a US merchant ship stands cargo watch as freight is lowered into an open hatch, c.1981
General
Other namesBosun
Deck Boss
Chief rate
DepartmentDeck department
LicensedNo
RequirementsTypically, able seaman certificate
Watchstanding
Watch (at sea)On smaller vessels (varies)
Watch (in port)On smaller vessels (varies)

A boatswain (/ˈbsən/ BOH-sən, formerly and dialectally also /ˈbtswn/ BOHT-swayn), bo's'n, bos'n, or bosun, also known as a deck boss, or a qualified member of the deck department, is the most senior rate 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. Additional duties vary depending upon ship, crew, and circumstances.