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. The navigation rules for meeting head-on, crossing, and overtaking situations are examples of when sound signals are required.
If on State Waters
16 feet up to 26 feet long and under engine power
Whistle capable of producing a blast of two seconds or more and audible for at least one-half mile is required.
26 feet or longer and under engine power
Whistle audible for at least one mile is required.
If on Federally Controlled Waters
Less than 39.4 feet (12 meters) long (includes PWC)
Efficient sound device, such as a handheld air horn, an athletic whistle, or an installed horn, is required; human voice is not acceptable.
39.4 feet (12 meters) long or longer
Sound signal should be audible for one-half mile and should last for 4 to 6 seconds.