Sound Producing Devices

In periods of reduced visibility or whenever a vessel operator needs to signal his or her intentions or position, a sound producing device is essential. Know the rules for meeting head-on, crossing, and overtaking situations. The sound producing device may be a whistle, horn, or bell that is audible for 1/2 mile. All vessels on state and federally controlled waters must have a sound producing device to communicate.

Common Sound Signals

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

A short blast, lasting one second.
A prolonged blast lasting 4-6 seconds.

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 backing up.”

Restricted Visibility

One prolonged blast at intervals of not more than two minutes is a signal used by power driven vessels when underway.
One prolonged blast, plus 2 short blasts at intervals of not more than two minutes apart, is the signal used by sailing vessels.

Make way for large commercial vessels -who will sound their horns to boaters to move out of the main shipping channel.

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.

Graphic of different sound signaling devices