Skip to main content

Course Outline

Sound Signal 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. The navigation rules for meeting head-on, crossing, and overtaking situations are examples of when sound signals are required.

These requirements apply to vessels operating on North Dakota state waters.

  • Vessels less than 16 feet in length, which includes PWC, are not required to carry a sound-producing device, but it is strongly recommended that they do so.
  • Vessels 16 feet up to 26 feet in length are required to carry on board a mouth-, hand-, or power-operated whistle audible for at least one-half mile.
  • Vessels 26 feet up to 40 feet in length are required to carry on board a hand- or power-operated whistle audible for at least one mile and a bell.
  • Vessels that are 40 feet or more in length are required to carry on board a power-operated whistle audible for at least one mile and a bell.

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.
  • Unit 4 of 6
  • Topic 11 of 19
  • Page 5 of 6