EPIRBs (Emergency Position Indicating Radio Beacons) are portable satellite communication units (see a selection below), designed to send an automated distress signal to search and rescue authorities ashore. The RNLI recommends that small craft carry an EPIRB if they sail more than 60 miles from the coast. EPIRBs are activated either manually, when it is physically lifted out of its bracket, or automatically, when the vessel sinks.

The floating beacon emits a homing signal helping the rescue authorities to locate the vessel..