A boatswain's call, pipe or bosun's whistle is a pipe or a non-diaphragm type whistle used on naval ships by a boatswain. It is pronounced, and sometimes spelled, "bosun's call".

Historically the boatswain's call was used to pass commands to the crew when the voice could not be heard over the sounds of the sea. Because of its high pitch, it could be heard over the activities of the crew and bad weather. It is now used in traditional bugle calls such as Evening Colors/Sunset, and in other ceremonies in most modern navies.

Used by Navies around the world including Australian, British, Malaysian, US and South African Navies. This is the perfect gift for the boater in your life.