a compact, buoyant, self contained radio transmitter which continuously emits a distinctive radio signal to a satellite for at least 48 hours when activated. It allows rescuers to find you. FOR EMERGENCY USE ONLY.
a buoyant radio distress beacon that transmits a signal to satellite receivers that, in turn, relay the signal to rescue co-ordination centres
a device carried on a boat, which can be either operated manually or set to operate if immersed in water