Types of EPIRBs

Emergency position indicating radiobeacons or EPIRBs, are devices intended to save your life by alerting rescue authorities and indicating your location. EPIRBs range in price from $200 to $1500. The various types of EPIRBs are explained below:

EPIRBs NO LONGER IN USE OR RECOGNIZED BY THE FCC
 

Class A

121.5/243 MHZ. Automatically-activating, free-floating, detectable by aircraft and satellite. Limited coverage. Alerts from this EPIRB to a rescue coordination center can be delayed 4 - 6 or more hours. These devices have been phased out by the FCC and are no longer recognized.

Class B

121.5/243 MHZ. Manually activated version of Class A. These devices have been phased out by the FCC and are no longer recognized.

Class C

VHF ch15/16. Manually activated, operates on maritime channels only. Not detectable by satellite. These devices have been phased out by the FCC and are no longer recognized.

Class S

121.5/243 MHZ. Similar to Class B, except it floats, or is an integral part of a survival craft. These devices have been phased out by the FCC and are no longer recognized.
 

RECOGNIZED EPIRBs BY FCC AND GMDSS
 

Category I

406/121.5 MHZ. Free-floating, automatically activated EPIRB. Detectable by satellite anywhere in the world. Recognized by GMDSS.

Category II

406/121.5 MHZ. Similar to Category I, but manually activated. Some models are also water activated.

Inmarsat E

1646 MHZ. Free-floating, automatically activated EPIRB. Detectable by Inmarsat geostationary satellite. Recognized by GMDSS. Currently not sold in the U.S.; however, the Federal Communications Commission is considering recognizing these devices. This service ended 12/31/2006.
 

121.5/243 MHz EPIRBs

The most common and least expensive type of EPIRB, which is designed to be detected by overflying commercial or military aircraft, is the 121.5/243 MHz EPIRB. Satellites were designed to detect these EPIRBs, but are limited for the following reasons:

  1. Satellite detection range is limited for these EPIRBs as satellites must be within line of sight of both the EPIRB and a ground terminal for detection to occur.
  2. Frequency congestion in the band used by these devices cause a high satellite false alert rate (99.8%); requiring confirmation before search and rescue forces can be deployed.
  3. EPIRBs manufactured prior to October 1989 may have design or construction problems or may not be detectable by satellite. Such EPIRBs may no longer be sold.
  4. Because of location uncertainties coupled with frequency congestion in this band, two or more satellite passes are necessary to determine if the signal is in fact from an EPIRB and to determine the location, delaying rescue by an average of 4 to 6 hours. In some cases, a rescue can be delayed as long as 12 hours or more.
  5. COSPAS-SARSAT is expected to cease detecting alerts by 2008.

November 3, 2000, the National Oceanic and Atmospheric Administration (NOAA) announced that satellite processing 121.5/243 MHz emergency beacons will be terminated on February 1, 2009. Class A and B EPIRBs must be phased out by that date. The U.S. Coast Guard no longer recommends these EPIRBs be purchased.

As part of the United States efforts to prepare beacon users for the end of 121.5 MHz frequency processing by satellites, the FCC has prohibited the use of 121.5 MHz EPIRBs as of January 1, 2007 (47 CFR 80.1053, .1055, and .1059)

406 MHz EPIRBs

The 406 MHz EPIRB is designed to operate with satellites. The signal frequency of 406 MHz has been given designation internationally only for distress. Other communications and interference, is not allowed on this frequency. Its signal allows a satellite local user terminal to accurately locate the EPIRB with increased accuracy between 2 to 5 km versus 25 km than 121.5/243 MHz devices, and identify the vessel’s identity, which is coded in the signal, anywhere in the world with no range limitation. These devices are detectable by COSPAS-SARSAT satellites and by geostationary GOES weather satellites. EPIRBs detected by the GEOSTAR system, send rescue authorities an instant alert, but without location information, unless provided by an integral GPS receiver, the rescue is not as swift. EPIRBs detected by COSPAS-SARSAT satellites provide rescue authorities location of distress. These EPIRBs also include a 121.5 MHz homing signal, which allows aircraft and rescue craft to quickly locate the vessel in distress. These are the only type of EPIRB which must be certified by Coast Guard approved 3rd party laboratories before they can be sold in the United States.

A new type of 406 MHz EPIRB, with an integral GPS navigation receiver, became available in 1998. This EPIRB sends accurate location information as well as identification to rescue authorities immediately upon activation through both GEOSTAR and COSPAS-SARSAT satellites. These types of EPIRB are the best you can buy.
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Acr Globalfix 406 2742 Epirb Category 1
 
406 MHz emergency locating transmitters (ELTs) for aircraft are currently available. 406 MHz personnel locating beacons or PLBs are available.
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Revere Mcmurdo Fastfind 406 Plb Without Gps

The Coast Guard recommends you purchase a 406 MHz EPIRB, preferably one with an integral GPS navigation receiver. A Cat I EPIRB should be purchased if it can be installed properly.

406 MHz GEOSAR System

The provision of global Earth coverage using a limited number of polar-orbiting satellites is the major advantage of the 406 MHz low earth orbit system. Although coverage is not continuous, and it may take up to a couple of hours for an EPIRB alert to be received, COSPAS-SARSAT has 406 MHz EPIRB repeaters aboard three geostationary satellites, plus one spare. Ground stations are also capable of receiving 406 MHz except for areas between the United Kingdom and Norway, south of the east coast of Australia, and the area neighboring the Sea of Okhotsk near Russia, as well as polar areas, GEOSAR still provides continuous global coverage of distress alerts from 406 MHz class EPIRBs.