Emergency Position Indication Radio Beacons (EPIRBs)
from Fleet Surgeon Barbara Jean Wilk, M.D.

Emergency Position Indication Radio Beacons (EPIRBs) are devices that cost from $200.00 to about $1500.00 and are designed to save your life by alerting rescue authorities and indicating your location in emergencies . The types or EPIRBs are summarized below:

Class A

121.5/243 MHZ. Free-floating and automatically activated. Detectable by aircraft and satellite. Range limited. The time from alert from this device to a rescue coordination may be delayed 4-6 hours or more. No longer recommended.

Class B

121.5/243 MHZ. Manually activated version of Class A. No longer recommended.

Class C

VHF Ch 15/16. 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. No longer recommended.

Category I

406/121.5 MHZ. Free-floating. Automatically actived EPIRB. Detectable by satellite anywhere in the world. Recognized by GMDSS.

Catagory II

406/121.5 MHZ. Similar to Catagory I, except is manually actived. Some models are also water activated.

Inmarsat E

1646 MHZ. Free-floating. Automatically activated and detectable by Inmarsat geostationary satellites. Recognized by GMDSS. Not currently sold in the U.S., but the FCC is considering recognizing these devices.

More on 406 MHZ System set-up

The major advantage of the 406 MHZ, low earth orbit system is the provision of global Earth coverage by a limited number of polar-orbiting satellites. In certain circumstances, the orbiting satellite coverage is not continuous and it may take hours for an EPIRB alert to be detected, if an orbiting satellite has just passed over the site. To overcome this limitation of the COSPAS-SARSAT orbiting satellites, 406 MHZ EPIRB repeaters were placed aboard three geostationary satellites (GEOSTAR system). Except for areas between the United Kingdom and Norway, the east coast of Australia and parts of Russia, the GEOSAR provides pretty much continuous global coverage of distress alerts from 406 MHZ EPIRBs. The 406 MHZ EPIRBs also have a 121.5 MHZ homing signal, allowing aircraft and rescue craft to quickly find the vessel in distress. A new type of 406MHZ EPIRB, having an integral GPS navigation receiver, became available in 1998. It will send accurate location and identification information to rescue authorities through activation of both the orbiting and the geostationary satellites. The two types of 406MHZ EPIRBs are certified by U.S. Coast Guard approved, independent laboratories before sale in the U.S.. The ones that contain an integral GPS or interface with a GPS system are considered the best and are advised by the USCG.

To register a 406 MHZ EPIRB, you can do either download a copy of the registration form available at the website sited at the beginning of this article or call toll free 1-888-212-SAVE for further information and a copy of the form.