What is an EPIRB?? and why does their cost approach $1000.00? An EPIRB is a Emergency Position Indicating Radio Beacon....anyone who has followed the rescue of Abby Sunderland should know that a pair of EPIRB's is what most likely saved her life. The way a EPIRB works is that when the shit hits the fan you either set the EPIRB off manually or simply tie it to the life raft and throw it in the water.....kick back....open up a MRE and wait for SAR (search and rescue) to get there. When you consider the benefits of having an EPIRB on board of a cruising yacht....the cost isn't as shocking.