Boatswain
| The boatswain aboard a US merchant ship stands cargo watch as freight is lowered into an open hatch, c. 1981 | |
| General | |
|---|---|
| Other names | Bosun Deck Boss Chief rate | 
| Department | Deck department | 
| Licensed | No | 
| Requirements | Typically, able seaman certificate | 
| Watchstanding | |
| Watch (at sea) | On smaller vessels (varies) | 
| Watch (in port) | On smaller vessels (varies) | 
A boatswain (/ˈboʊsən/ BOH-sən, formerly and dialectally also /ˈboʊtsweɪn/ BOHT-swayn), bo's'n, bos'n, or bosun, also known as a deck boss, or a qualified member of the deck department, or the third hand on a fishing vessel, 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.