beacon rescuers onshore were notified. [siren] >> off the boat. frigid water like this you have a 15 minutes until severe hypothermia starts setting in. after that a host of complication and your ability to survive goes down dramatically. even the coast guard helicopter needs specific navigation to arrive on time. >> just seeing from here up, is very difficult to see that person in the water. >> reporter: the plb points them to the spot. coast guard swimmer mike thompson makes easy work of plucking a swimmer from the water. a difference between the rescue and recovery is getting him to the victim on time. it was just about 40 minutes between activating the beacon and the rescue. so without the drysuit i would have been in bad shape but a healthy person could survive that kind of a thing of the beacon, plb, 150 and $400.