Emergency position-indicating radio beacon

An emergency position-indicating radio beacon (EPIRB) is a type of emergency locator beacon for commercial and recreational boats; it is a portable, battery-powered radio transmitter used in emergencies to locate boaters in distress and in need of immediate rescue. In the event of an emergency, such as a ship sinking or medical emergency onboard, the transmitter is activated and transmits a continuous 406 MHz distress radio signal, which is used by search-and-rescue teams to quickly locate the emergency and render aid.

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