EPIRBs (pronounced ee-pirbs), formally Emergency Position Indicating Radiobeacons, are devices that trasmit a digital signal on the international distress signal frequency 406 MHz. Designed to work with satellites, EPIRBs are detectable by COSPAS-SARSAT satellites, which orbit the poles, and by the GEOSAR system which consists of GOES weather satellites and other geostationary satellites.
There are two types of EPIRBs - Category I or Category II that are approved for use in the United States today. Both transmit only on 406 MHz. In February of 2009, the FCC phased out the use of EPIRBs that transmitted on 121.5 MHz frequency (Class A, B, and S), and these devices may no longer be used, marketed or manufactured in the U.S. If you have one of these, please replace it with an approved 406 MHz device.
Category I EPIRBs float-free and are automatically activated by immersion in water, and they are detectable by satellite anywhere in the world. Category II EPIRBs are similar to Category I, except in most cases they are manually activated, however some models can be automatically activated.
EPIRBs use a special type of lithium battery designed for long-term, low-power consumption operation. The battery must be replaced by a dealer approved by the manufacturer during the specified time or it will not work properly. Also, consumers should be aware when ordering EPIRBs online, added shipping charges may apply for hazardous material. Some EPIRBs and PLBs are being manufactured that do not use hazardous material batteries.
Proper registration of your 406 MHz satellite emergency position-indicating radio beacon (EPIRB) is intended to save your life, and is mandated by Federal Communications Commission (FCC) regulations. The Coast Guard is enforcing this FCC registration rule. According to the Coast Guard, "if the EPIRB is properly registered, [they] will be able to use the registration information to immediately begin action on the case. If the EPIRB is unregistered, a distress alert may take as much as two hours longer to reach the Coast Guard over the international satellite system. If an unregistered EPIRB transmission is abbreviated for any reason, the satellite will be unable to determine the EPIRB's location, and the Coast Guard will be unable to respond to the distress alert. Unregistered EPIRBs have needlessly cost the lives of several mariners since the satellite system became operational."
Further reading about EPIRBS and Personal Locator Beacons (PLBs):
How to Register an EPIRB or PLB
Should You Purchase an EPIRB or a PLB?
The Best EPIRBs or PLBs to Buy
Marine Electronics Review - SPOT Personal Locator Beacon
Marine Electronics Review - ACR Electronics AquaFix 406 I/O Personal Locator Beacon
Marine Electronics Review - ACR Electronics ResQFix 406 GPS Personal Locator Beacon
Marine Electronics Review - ACR Electronics GlobalFix iPRO EPIRB
