406MHz distress beacons are are self-contained radio transmitters designed for emergency use only. They come in three forms:
- EPIRB (Emergency Position Indicating Radio Beacon),
- PLB (Personal Locator Beacon), and
- ELT (Emergency Locator Transponder)
So what are they?
All three beacon types operate on the 406MHz frequency and are detected by the proven Cospas-Sarsat satellite system. This global system detects signals from the beacons, and ensures that the relevant Search and Rescue Authority takes action to rescue the people who are associated with the beacon. In Australia, the beacons are processed by the Australian Mission Control Centre, at AMSA – The Australian Maritime Safety Authority.
EPIRBS are designed to operate in the marine environment. They are carried by ships and boats. Some are designed to float free and automatically activate if the vessel sinks, whilst others are manually activated. Their battery is designed to operate the beacon for a minimum of 48 hours. Many maritime rescues take a considerable period of time, as French sailor Alain Delord discovered during his recent capsize and rescue in the southern ocean: http://www.abc.net.au/news/2013-01-20/french-sailor-rescued-after-days-adrift-off-tas/4473120. The beacons must be registered with a competent authority (in Australia this is AMSA*)
PLBs are designed to be carried by people, and as such are smaller and more compact that EPIRBs. They operate in much the same way as EPIRBs, however they are not designed to operate in the marine environment and indeed many of them sink if they are separated from their pouches. As they are not designed to float upright like EPIRBs, they are not a substitute for them when boating, however can and are often carried by crew when working on deck, particularly on yachts.
Whilst there is no legislation requiring PLBs be registered when used in a land environment, common sense dictates that you should register your beacon. Registered beacons mean the Search and Rescue teams are not only quicker to respond, but they are able to tailor their response to their your specific needs. For example, if you list on your registration that you’re diabetic, the Search and Rescue team will be able to ensure they have the correct medication with them. Registration is free and can be done here: http://beacons.amsa.gov.au/*
ELTs are fitted to aircraft, and they are commonly fitted with a crash activated switch. Like EPIRBs, the ELT must be registered with a competent authority.
So which one do I need?
All these beacons serve a different purpose, and are optimised for the environment in which they are intended to operate. You can take an EPIRB bush walking, but it is heavy and bulky. You cannot take a PLB on a vessel in lieu of a EPIRB due to its design. The Australian Maritime Safety Authority puts out an excellent fact-sheet on beacons that can be downloaded here: http://www.amsa.gov.au/publications/Fact_sheets/Beacons_FaQ.pdf
The beacon is a very useful tool for alerting that you are in distress – a recognised term that means you are in Grave or Imminent Danger. There are however many other devices that can alert family and friends that you need assistance. A more detailed explanation of what other devices are available and how they operate can be found here: http://campingcommunication.com/
* International visitors can register their beacon here: https://www.406registration.com/