There is a hierarchy of communication on the offshore sailing vessel. The first resort is the VHF radio — short range, immediate, heard by every vessel in the area. The second resort is the satellite phone: global range, one-to-one, connects to the coast guard or the rescue services directly.
The EPIRB is the last resort. It is deployed when the first two have failed or are unavailable, when the vessel is sinking or has been abandoned, and when the crew in the water or in the life raft needs to be found by search and rescue services who do not yet know where to look.
EPIRB stands for Emergency Position Indicating Radio Beacon. The name describes it accurately: it is a radio beacon that indicates the emergency position. The device transmits a digital signal on 406 MHz — a frequency allocated internationally for distress alerting, that is received by the COSPAS-SARSAT satellite network. COSPAS-SARSAT is the international satellite system operated jointly by the United States, Russia, the European Union, and India, comprising dozens of satellites in low and medium Earth orbits that provide global distress signal detection coverage.
The signal from the EPIRB reaches the network regardless of where in the world the Eighty2 is: the outer Pacific, the Banda Sea, the Red Sea offshore sites. There is no location on the planet’s surface from which the 406 MHz signal cannot be received by the COSPAS-SARSAT constellation.
The Automatic Release and Why It Matters
The Eighty2’s EPIRB is mounted in a Category I bracket on the stern, a specific bracket type that releases the EPIRB automatically if it is submerged to approximately one metre of water depth. The hydrostatic release mechanism is activated by the water pressure: when the bracket reaches one metre depth, the mechanism releases the EPIRB, which floats free of the sinking vessel and activates automatically when it reaches the surface. If the boat sinks quickly with the crew unable to manually deploy the EPIRB, the EPIRB deploys itself.
The crew does not need to remember to grab it in the chaos of the abandonment. The water does it for them.
The digital distress signal transmitted by the EPIRB contains the vessel’s MMSI registration number and the GPS position from the EPIRB’s own internal GPS receiver. The COSPAS-SARSAT network relays the signal to the Mission Control Centre responsible for the region, which forwards the alert to the Rescue Coordination Centre with the vessel’s identity, position, and the timestamp of the activation.
The rescue services know who, where, and when before the first rescue vessel has left the dock. The EPIRB registration, linking the MMSI number to the vessel details and the emergency contacts, must be current for this to work correctly. We check it annually.
The battery is checked and replaced on the manufacturer’s schedule. The bracket release mechanism is tested on the schedule it requires. This is the piece of safety equipment that is never allowed to be out of condition, because the condition it exists for is the condition in which every other system has already failed.
