Important Change To Rescue Beacons

The international council that controls the Cospas-Sarsat rescue satellite system has disabled the 121.5 MHz EPIRB signal. Only 406 MHz beacons can now be detected by the satellite.

The decision was made to reduce the chronically high false alarm rate from analogue distress beacons. Under the old system, 97 per cent of analogue distress beacon signals were false alarms.

As every beacon alert in and around Australia is treated as a genuine emergency until proven otherwise, these false alarms tied up scarce search and rescue assets such as helicopters. The Australian Marine Safety Authority (AMSA) was concerned that someone at sea in a genuine emergency could get an undersized search and rescue response because search and rescue assets were tied up chasing a false alarm. This has not occured in Australia, but the concern by many authorities around the world that it could happen has led to the international decision to eliminate the analogue frequency.

The digital beacons transmit an identity code on the 406 MHz frequency that can be cross-referenced with a database of registered 406 MHz beacon owners by AMSA. This database includes phone numbers, next of kin contacts, information on the type of vessel, how many people it usually carries and other vital information that enable the right response to the emergency to be provided. In the case of false alarms, it enables AMSA to call the registered beacon owner to see if he/she is in genuine distress or just has a beacon transmitting by accident. Many maritime false alarms occur because the switch on the distress beacon has been bumped on.

Most significantly however, 406 MHz beacons are detected more quickly and accurately (to within 5 kilometres by satellite compared to 20 km for the analogue beacons) which has an obvious safety advantage. Depending upon location, the 406 MHz beacon may be detected within minutes compared to the average one hour and 30 minutes it takes to get a confirmed satellite detection from a 121.5 MHz analogue beacon.

It is now imperative that you replace your old 121.5 MHz EPIRB with the new 406 MHz system. The owner's details must be registered with the Australian Maritime Safety Authority.
More details can be found here.


Click to enlarge image: 406 MHz beacons can now be detected by satellite.

406 MHz beacons can now be detected by satellite.