Analog EPIRBs no longer being monitored

After a nine-year transition period, analog-style Emergency Position Indicating Radio Beacons (EPIRBs) are no longer being monitored by search and rescue agencies.

Since Feb. 1, the U.S. Coast Guard and other search-and-rescue personnel have been receiving distress alerts broadcast using digital 406-MHz EPIRBs only. Satellites no longer process signals from analog EPIRBs that transmit only on 121.5 or 243 MHz.

Manufacturers stopped making analog units about five years ago and refused to service them as the changeover deadline approached. Most commercial users had switched over long before the deadline, but some smaller vessels and recreational cruising boats continued to use them until the deadline. The Coast Guard did not keep records of the units still in operation because there was no requirement to register them, unlike the new units.

The 406 EPIRB’s signal is 50 times more powerful and also more accurate than the 121.5 signal.

“With 121.5 beacons, an initial position uncertainty can result in a 500 square mile search area,” said Rick Arsenault, a search and rescue specialist at the First Coast Guard District Command Center in Boston. “With a digital beacon, that initial search is reduced to 25 square miles.”

And a GPS-embedded 406 EPIRB can reduce a search area to about 100 yards and pinpoint the position of a distressed mariner within minutes.

Additionally, the number of false alerts with digital beacons is significantly lower than analog units. Satellites were not capable of distinguishing between beacon and non-beacon sources using analog frequencies. So only about one in five alerts actually came from a beacon. Many false alarms came from ATMs, pizza ovens and stadium scoreboards. With analog beacons, the only way to determine if an alert was real was to send rescue crews to the area, which cost thousands of dollars and took resources away from actual emergencies.

The newer models start at about $500 and more expensive ones that include GPS cost $1,200 to $1,500. Owners are required by law to provide emergency contact information and a vessel description by registering their beacons with the National Oceanic and Atmospheric Administration (NOAA). This lets search and rescue personnel quickly confirm if a distress signal is real and identify who and what type of boat or aircraft to look for. If an EPIRB is accidentally activated, rescue agencies can find out quickly with a phone call to the owner.

EPIRB users can register their beacons in the U.S. 406 MHz Beacon Registration Database at: or by calling 1-888-212-SAVE. Beacon registrations must be updated at least every two years or when information such as emergency contact phone numbers and other vital information changes. Registration information is available only to authorized search and rescue personnel.

There are already more than 75,000 EPIRBs in the NOAA 406 MHz registration database. •

Bill Bleyer

By Professional Mariner Staff