An emergency position-indicating radio beacon (EPIRB) is a small, battery-powered radio transmitter that is activated by immersion in water or manually. It transmits on 406.025 MHz and does not require a license. While not required for recreational boats, some commercial and fishing vessels operating beyond 3 miles must carry EPIRBs. Newer 406 EPIRBs contain unique codes that aid search and rescue efforts by identifying vessel characteristics and reducing false alarms. It is important to register new or used 406 EPIRBs with NOAA and update information if vessel details change.

1. Emergency Position Indicating Radio Beacon (Sixth Edition, 2008)
An emergency position-indicating radio beacon (EPIRB) is a small (about 6 to 20 inches
high), battery-powered radio transmitter that is activated either by immersion in water or by a
manual switch. It requires no license. You should buy an EPIRB that transmits on 406.025 MHz,
common call 406s.
Recreational boats are not required to carry EPIRBs; some commercial and fishing
vessels must have them if they operate beyond the 3-mile limit, however, and vessels carrying
six or fewer passengers for hire must have EPIRBs under some circumstances when operating
beyond the 3-mile limit.
Some EPIRBs contain a 121.5 MHz frequency, which was intended to be monitored by
commercial aircraft. But its use by recreational boaters is prohibited by the Coast Guard as of
2007. The Coast Guard highly recommends that recreational vessels carry 406s, whose signals
can be receives worldwide by satellites. When a satellite receives a 406 signal, it records the
signal and retransmits it to the first land –based receiving station the satellite passes over. A
406’s signal can be pinpointed anywhere on the earth’s surface to within3 nautical miles on the
first pass and within 1 mile on the third.
Newer 406 signals are uniquely coded for each unit. The individual information is
recorded in National Oceanic and Atmospheric Administration (NOAA) computers; it aids in
search-and-rescue efforts by identifying your vessel’s characteristics and also helps reduce false
alarms.
Too often, EPIRBs are turned on during designated test periods and then are not turned
off. When you test your 406, be certain that it is in the “test” mode.
If you buy a new or used 406 EPIRB or change your boat, address, or telephone number,
you must register it with NOAA. To request and submit 406 MHz EPIRB registration forms, go
to www.beaconregistration.noaa.gov, or call 888-212-7283
Reference
Sixth Edition, C. G. (2008). Sailing Skills and Seamanship. Camden: McGraw-Hill.