Rules of the Road: Distress signals rely on EPIRBs being programmed, registered

Aug 2, 2017 by Capt. Jake DesVergers

Rules of the Road: by Capt. Jake Desvergers

EPIRB. We hear the acronym dropped constantly, but what is this critical piece of lifesaving equipment?

An Emergency Position-Indicating Radio Beacon (EPIRB) is a tracking device that aids in the detection and location of vessels in distress. In simplest terms, they are radio beacons that interface with the worldwide system known as Cospas-Sarsat. This service is a satellite-based search and rescue (SAR) distress alert system. It was established in 1979 by the governments of Canada, France, the United States and the former Soviet Union. Cospas-Sarsat is the primary system that detects and locates emergency beacons activated by aircraft, ships and people engaged in recreational activities in remote areas.

The system consists of a distress beacon, a space segment, and a ground segment.

The distress beacon is a digital 406-MHz radio transmitter that is activated in a life-threatening emergency. Beacons are classified in three main categories based upon use: aircraft, marine vessels, and individuals. Beacons designed for use in an aircraft are known as an Emergency Locator Transmitter (ELT). Those designed for use aboard a marine vessel are called an Emergency Position-Indicating Radio Beacon (EPIRB). And units that are designed to be carried by an individual are known as a Personal Locator Beacon (PLB).

The space segment consists of several satellites at various orbits around the earth. There are five satellites in polar low-altitude orbit, nine satellites in geostationary orbit, and over thirty satellites in medium-altitude orbit. These satellites record the data from a distress signal and relay that information to a ground station when the satellite passes overhead.

The ground segment consists of receiving stations equipped to track the satellites via a Local User Terminal (LUT). These terminals are installed by individual national administrations or agencies. The distress messages received by a LUT are transferred to an associated mission control center. That center then routes the message to the Rescue Coordination Center (RCC) physically closest to the distress location.

To ensure that a distress signal is properly transmitted and received, it is essential that the unit is properly programmed and registered. International regulations dictate that EPIRBs must be programmed for the country under the flag of which a vessel sails.

When an EPIRB is initially purchased, the unit is normally programmed for the country where it is being sold. For example, most units sold in the United States have a default country code of 338, 366, 367, 368, or 369. However, if the yacht is flying the flag of a different country, the unit must then be reprogrammed. This requires the EPIRB to be physically connected to a computer with the manufacturer’s software. Examples of country codes are:
232    United Kingdom
236    Gibraltar
248     Malta
304    Antigua and Barbuda
316    Canada
319    Cayman Islands
339    Jamaica
375    Saint Vincent & the Grenadines
387    British Virgin Islands

The first three numbers in the yacht’s MMSI is the country code.

Once the EPIRB is properly programmed, it needs to be registered. This is normally done directly online at Some countries, such as the United States, offer online registration through their own dedicated website: In all cases, the information submitted is maintained within the international database for access by all member countries.

Upon completion of the registration, the EPIRB must be installed on board. The ideal location for an EPIRB to be stored on a yacht is on the open deck, unobstructed from any overhead structure. This allows for a float free operation.

The EPIRB should also be attached to the yacht via a hydrostatic release unit (HRU). The HRU is a pressure-activated mechanism designed to automatically deploy when certain conditions are met. This occurs when the HRU is submerged to a maximum depth of 4 meters. The pressure of the water against a diaphragm within the sealed casing causes a plastic pin to be cut. Following this designed action, the containment bracket releases the casing and allows the EPIRB to float free.

Capt. Jake DesVergers is chief surveyor for International Yacht Bureau ( Comments are welcome below.


About Capt. Jake DesVergers

Capt. Jake DesVergers is chief surveyor for International Yacht Bureau (IYB), an organization that provides flag-state inspection services to yachts on behalf of several administrations. A deck officer graduate of the U.S. Merchant Marine Academy at Kings Point, he previously sailed as master on merchant ships, acted as designated person for a shipping company, and served as regional manager for an international classification society. Contact him at +1 954-596-2728 or

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