Boatswain's Call Law and Legal Definition
Boatswain's call is a whistle used by the English Royal Navy to show respect for special onboard visitors, the Captain, or a corpse being brought on board or sent out.
It was initially used by the boatswain, the officer in charge of the sailing equipment and riggings, to pass orders to men on board when the human voice was the only means of communicating on a ship.
The Boatswain Call may also be used to emphasize important orders.