WHISTLE, HORN, AND BELL (SIGNALING DEVICES)

The navigation rules require sound signals to be made under certain circumstances. Meeting, crossing and overtaking situations described in the Navigation Rules section are examples of when sound signals are required. Recreational vessels are also required to sound signals during periods of reduced visibility.

Vessels 39.4 feet/12 meters or more in length are required to carry onboard a whistle or horn. The requirement to carry a bell in international waters was recently dropped. Any vessel less than 39.4 feet/12 meters in length must carry a whistle or horn, or some other means to make an efficient sound signal to signal your intentions and to signal your position in periods of reduced visibility.

Examples of an efficient sound include a mouth whistle or compressed air horn. All sound producing devices must be audible for at least one-half mile on a clear, windless day.