Requirement to Have 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. The navigation rules for meeting head-on, crossing, and overtaking situations described in Chapter 3 are examples of when sound signals are required. All vessels are required to carry an effective sound-producing device, such as a whistle or horn, that is audible for at least one-half mile. Larger vessels also may be required to carry a bell or gong per federal Navigation Rule # 33, which can be found at https://www.navcen.uscg.gov/?pageName=NavRulesWithAnnexes.