Auto Release
Auto Release EPIRBs are carried by all sea going ships subject to the SOLAS (Safety Of Life At Sea) Convention. The rule also applies to ferries and other classes of vessel according to national regulations - for instance in the UK, it applies to all fishing vessels over 12m in length.
The EPIRB is mounted on an open bracket or in a protective container fixed in any position likely to allow it to float free if the vessel sinks. A hydrostatic release unit (HRU) is activated by water pressure at a depth between 2 and 4 metres.
Once out of its bracket, the EPIRB floats to the surface and starts transmitting immediately, activated by contacts which sense that the unit is floating in water. These "seawater contacts" are disabled when the EPIRB is mounted in its bracket, to prevent false alerts.
Ocean Signal SafeSea E100 Auto
