This traditional boatswain's whistle is made of brass and nickel-plated for resistance to air and water. Air is forced through a mouthpiece into a constricted tube, from the end of which it strikes an open ball at high speed. A time-tested signaling device, perfect for all water sports.

- Material: Brass, nickel-plated
- Dimensions: 12.5 cm x Ø 2.5 cm
- Weight: approx. 20 g