EPIRB: The Modern Lifesavers

EPIRBs are specifically designed to save your life in an emergency situation. They can do so by instantaneously alerting the authorities and indicating your latitudinal and longitudinal position. There are several types to consider. There are also several types that are no longer recommended by the US Coast Guard. There are even more types that are no longer recognizable by modern detection equipment. We will examine these differing types, but first a small lesson in history:

Soon after the sinking of the Titanic in 1912, legislation was enacted by congress requiring all US ships to use Morse code radiotelegraph equipment for distress calls. The International Telecommunications Union then enacted requirements for all ships of all nations to do the same. This required never-ending monitoring from stations and highly trained personnel to transmit the signals. As more and more ships sailed the seas, this became a pain-staking practice to say the least. It was limited in effect as well by the medium frequency (MF) distress band of 500 MHz.

It was later in history that saw the formation of an organization charged with international safe shipping practices as well as pollution reduction at sea: The International Maritime Organization (IMO). In 1979, it was decided that a global method for distressed ships was to be created. Ship-to-ship and ship-to-shore distress signals are now aided by a combination of satellite and terrestrial radio signals, hence the catalyst for the development of EPIRBs.

We all know that technology is in a constant state of flux and evolution. A lot has changed since 1979, and is bound to continue the trend of change. Let’s go over some of the outdated EPIRBs as dictated by the US Coast Guard:

1) Class A EPIRB: 121.5/243 MHz. Free-floating. Automatic activation. Detectable from aircraft and satellite. Limited coverage. Possible delays in alert of 4 – 6 hours. No longer recommended.
2) Class B EPIRB: 121.5/243 MHz. Same as Class A with manuel activation. No longer recommended.
3) Class C EPIRB: VHF Channels 15 & 16. Manuel activation required. Not detectable by satellite. Phased out and no longer recognized by the FCC.
4) Class S EPIRB: 121.5/243 MHz. Very similar to Class B except it is buoyant. No longer recommended.
5) Category I EPIRB: 406/121.5 MHz. Auto-activation. Free-floating. Globally detectable by satellite. Recognized by GMDSS (Global Maritime Distress and Safety System).
6) Category II EPIRB : 406/121.5 MHz. Same as Category I with manuel, and sometimes water, activation.
Inmarsat E EPIRB: 1646 MHz. Free-floating. Auto activation. Globally detectable.

The 121.5/243 MHz EPIRBs are least expensive and therefore most common type. By design they are to be detected from commercial or military aircraft. Satellites were developed to detect them, but are limited for many reasons. Expected to be phased out by 2008.

406 MHz EPIRBs are designed to operate with satellites. 406 MHz is the internationally accepted frequency for distress calls. This allows for far more effective location and speed that the 121.5/243 MHz units. These units do include a 121.5 MHz signal to alert aircraft. Still comes with possible signal delays of up to two hours although not common. Coast Guard recommended.

An improvement on stock 406 MHz units, the 406 MHz GEOSAR System units provide continuous coverage through the utilization of more than just polar-orbiting satellites. These provide global coverage with excellent response times. These units cannot detect advisories in the 121.5 MHz transmission range, nor can they route unregistered 406 MHz alerts to rescue authorities.

Established conjunctively by the U.S., Russia, Canada, and France, The COSPAS-SARSAT System EPIRB units provide international satellite-based search and rescue. COSPAS is a Russian acronym for Space System for Search of Distress Vessels; SARSAT signifying Search and Rescue Satellite-Aided Tracking. These units are superior to others and carry the price tag to prove it.

Units reviewed here range in price from $200 - $2000. Current EPIRBs are indispensable for all sea-faring vessels. When the storms blow up from nowhere, which is exactly where they come from, you will be thrilled to own the confidence that your EPIRB unit grants you. Don’t leave shore without an EPIRB unit onboard!