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Sound-Producing Devices

A sound-producing device is required on all waters. It is essential during periods of reduced visibility.

The sound-producing device must be audible for one-half mile.

  • Vessels less than 65.6 feet in length (including PWCs, sailboats, and manually powered vessels) are required to carry on board a mouth-, hand-, or power-operated whistle or horn, or some other means to make an efficient sound signal.
  • Vessels 65.6 feet or more in length are required to carry on board a whistle or horn, and a bell.

No vessel may be equipped with a siren, except vessels used by law enforcement officers.

Sound Producing Devices

Sound Signals

Some common sound signals that you should be familiar with as a recreational boater are as follows.

Changing Direction

  • One short blast tells other boaters "I intend to pass you on my port (left) side."
  • Two short blasts tell other boaters "I intend to pass you on my starboard (right) side."
  • Three short blasts tell other boaters, “I am operating astern propulsion.” For some vessels, this tells other boaters, “I am backing up.”

Restricted Visibility

  • One prolonged blast at intervals of not more than two minutes is the signal used by power-driven vessels when underway.
  • One prolonged blast plus two short blasts at intervals of not more than two minutes is the signal used by sailing vessels.

Warning

  • One prolonged blast is a warning signal (for example, used when coming around a blind bend or exiting a slip).
  • Five (or more) short, rapid blasts signal danger or signal that you do not understand or that you disagree with the other boater's intentions.