EPIRB stands for Emergency Position Indicating Radio Beacon. An EPIRB is designed to help rescuers find you in an emergency situation. These radios have saved countless lives since their arrival in the 1970s. EPIRBs are a must for any ship, boat, yacht, or personal water craft.
EPIRBs are sophisticated devices that contain:
· A 5-watt radio transmitter operating at 406 MHz (see How the Radio Spectrum Works for details on frequencies)
· A 0.25-watt radio transmitter operating at 121.5 MHz
· A GPS receiver
Once triggered, both of the radios start transmitting. Approximately 24,000 miles (39,000 km) up in space, a GOES weather satellite in a geosynchronous orbit can detect the 406-MHz signal. If the EPIRB is properly registered, the serial number lets the Coast Guard know who owns the EPIRB. Rescuers in planes or boats can home in on the EPIRB using either the 406-MHz or 121.5-MHz signal.
