EPIRBs, officially known as Emergency Position Indicating Radiobeacons, are emergency beacons used in maritime distress. They are designed to save your life if you get into trouble by alerting rescue authorities and indicating your location anywhere in the world. They utilize the COSPAS-SARSAT and GEOSAR satellite systems by sending a distress signal on 406 MHz frequency that is used to pinpoint your exact location. The coordinates are then sent to the appropriate agency to begin rescue efforts. EPIRBs can also be equipped with GPS technology that transmits your LAT/LONG for precise locating and faster rescue.
Further reading about EPIRBS and Personal Locator Beacons (PLBs):
How to Register an EPIRB or PLB
Marine Electronics Review - SPOT Personal Locator Beacon
Marine Electronics Review - ACR Electronics AquaFix 406 I/O Personal Locator Beacon
Marine Electronics Review - ACR Electronics ResQFix 406 GPS Personal Locator Beacon
Marine Electronics Review - ACR Electronics GlobalFix iPRO EPIRB
