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.
On Colorado state waters, these requirements for sound-producing devices apply.
- Motorboats that are 26 feet long or longer, but less than 40 feet long, are required to carry on board a hand- or power-operated whistle or horn audible for at least one mile and a bell.
- Motorboats that are 40 feet long or longer are required to carry on board a power-operated whistle or horn audible for at least one mile and a bell.
- All other vessels that are less than 40 feet long, except manually driven vessels when on white water, must have on board a mouth-, hand-, or power-operated whistle or horn audible for at least one-half mile.
These requirements apply to vessels operating on federally controlled waters.
- Vessels less than 39.4 feet (12 meters) in length, which includes PWC, must have some way of making an efficient sound signal. Examples are a handheld air horn, an athletic whistle, an installed horn, etc. A human voice is not acceptable.
- Vessels that are 39.4 feet (12 meters) or more in length must have a sound-producing device that can produce an efficient sound signal. The sound signal should be audible for one-half mile and should last for 4 to 6 seconds.