What you Need to Know About How an EPIRB Works

Radios & Transmitters

rescue helicopter searching for an EPIRB signal

An Emergency Position Indicating Radio Beacon (EPIRB) is used to alert search and rescue services in the event of an emergency. Since their introduction in the 1970s, EPIRB’s have assisted in rescues at sea and on land saving thousands of lives worldwide.

In July 2017 two men were left clinging to their upturned 5.5-metre boat two kilometres off Cronulla beach near Sydney for four hours. After one of the fishermen went diving under the hull around 9.45pm, he retrieved and activated their GME EPIRB. Within 45 minutes they were both rescued from extreme conditions including a seven-metre swell and were suffering mild to severe hypothermia.

The International Cospas-Sarsat Programme is a satellite-based search and rescue (SAR) and alert system that has been credited with rescuing over 35,000 people in the past 30 years. Until this year, the system used Low Altitude Earth Orbit Search and Rescue (LEOSAR) satellites but this has now been replaced with the Medium-altitude Earth Orbit Search and Rescue (MEOSAR) system that works at an altitude of between 19,000 and 24,000km. THe reason for this was that the LEOSAR system was aging and didn’t provide continuous coverage whereas the MEOSAR satellites are able to detect a location within 10 minutes, 95 percent of the time.

How Does an EPIRB Work?

An EPIRB on a boat can be activated either manually or automatically when it comes in contact with water after an incident has occurred. EPIRB housings also allow the unit to float when submerged.

When an EPIRB is activated, a 406MHz message is sent out including the beacon ID and GPS location (if the unit has GPS). A MEOSAR satellite detects the beacon and relays the message to earth via a MEOLUT (MEOSAR Local User Terminal), a satellite tracking ground station.

Made up of six antennas, the Australian MEOLUT uses each antenna to track a different satellite. When a burst is received from a distress beacon, it can calculate the location of the beacon and send the location coordinates and unit information to the Australian Maritime Safety Authority (AMSA) in Canberra. The AMSA alerts local authorities who can then begin a search and rescue.  

When a beacon doesn’t have GPS, the location is calculated using triangulation which can take significantly longer and be less accurate. Watch this short video if you are unsure if your beacon is GPS enabled.


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Registering your EPIRB

After purchasing your EPIRB the most important thing to do is register it in the country you will be using it. You will need to provide contact information for yourself and family members plus details of your vessel. Your family member may be contacted to confirm a rescue is required. Remember your EPIRB is suitable for use on land as well as sea so if you are planning a road trip that’s off the beaten track, take it with you.

When is an EPIRB Compulsory?

In Australia, it is compulsory to use an EPIRB when you are two nautical miles off the coast. The updated 406 MHz signal frequency meant skippers no longer had to rely on the VHF radio communication which can be unreliable past the continental shelf. Individual state and territories stipulate beacon carriage requirements. Contact your local marine authority for further details.  

New EPIRBs over Old

The technology continues to improve, and a GPS-equipped EPIRB can now get a location fix in less than 10 minutes. The older versions could take hours before rescuers knew where to start looking and the search area would have a radius of five kilometres. New models can tell where the beacon is within 150 metres and the battery life has improved to an impressive 10 years.   

Maintenance & Disposal

After purchase, it is important to read your user manual to ensure you maintain your EPIRB correctly. Most manuals will require that you keep the device away from:

·       Magnetic sources

·       Items that may knock the activation switch

·       High-pressure water sprays

·       Children that may play with it

The battery in an un-activated EPIRB should last a minimum of five years. Some need to be returned to the manufacturer to replace the battery while others allow you to replace the battery yourself.

It is important to perform regular self-tests of your EPIRB as part of your boat’s safety routine. You can watch a short video to demonstrate how to test your EPIRB. Only use authorised agents for servicing your beacon otherwise it may be deemed non-compliant. For more information, see GME’s refurbishment details, call GME on 1300 463 463 or email enquiries@gme.net.au for a list of authorised repairers around Australia.

When disposing of your EPIRB don’t throw it in the bin or recycling as it may be activated and need to be found at the tip. Contact your local maritime safety agency about disposal and update your online registration account or call 1800 406 406.

If you are looking to update your old one or buy your first EPIRB, check out our range of EPIRBs. Don’t hesitate to call us on 1300 308 161 or send us an email with any queries.

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