Emergency Position Radio Beacon

An Emergency Position Indicating Radio Beacon (EPIRB) is a safety device carried by a vessel to alert search and rescue services and allow them to quickly locate you in the event of an emergency.
When activated it transmits a coded message on the 406 MHz distress frequency which is monitored by the Cospas-Sarsat satellite system.
The alert is then relayed via an earth station to the nearest Rescue Coordination Centre (RCC).