I have volunteered for a marine SAR service in the U.K. and I’ve been on shouts looking for these things. We once looked for the old fashioned kind where you only get the location to within 50-100nm at first, with it getting a bit more accurate every 30(?)mins as the satellite passes over again. Searched all night only to find it fell of a shelf in someone’s shed.

In case anyone is interested here’s a simplified version of what happens if a beacon goes off in a U.K. sea area. The coastguard marine rescue coordination centre receives the alert, depending on the type of EPIRB initially the information could be as little as the location to within 100nm. If they get an ID number they look up the details to see which vessel/aircraft it’s registered to and they call the person listed on the register to find out if it’s an accidental activation. Meanwhile they are starting the process of tasking search and rescue units. Unless it can be confirmed it’s an accidental activation they will request at least one RNLI lifeboat and typically task a coastguard helicopter as well. They can also broadcast a Mayday on channel 16 to oblige all vessels nearby to take part in the search. The lifeboat service is a charity which is independent from the government so the coastguard has to contact the launch authority for the closest lifeboat station, the LA agree to be tasked and at that point crew pagers go off. The crew tumble out of bed (or work) and run or drive to the station. From at work or asleep at home to fully kitted up doing 25kts at sea is about 10mins. The coastguard can set our pagers off directly to save a few minutes if it’s super urgent, but the decision to put to sea is still made by the RNLI. Our patch extends out into the Atlantic as far as our range will take us, about 125nm at full speed, and about 30 mins north or south to the next boat’s patch. A fairly typical shout will see us on scene in under 45mins from launch. In our location the helicopter usually makes it there at about the same time as us give or take 10mins. The longest shout I’ve been on is 18 hours. A more typical one would be 3-4hours and our boat has two 1600hp diesels so we might use 1000 litres of diesel (costing about £500), about 1/6th of the tank mostly in getting there and back. The boat has a crew of 7. Apart from the Coxswain (the RNLI word for skipper) and the Mechanic the crew are all unpaid volunteers, we get a token amount of money per hour at sea, maybe £1, not sure. There is a pool of about 25 crew and we train for about 4 hours per week. As to what we can do when we get there. Our training covers seamanship, things like rope work, navigation, watch keeping, emergency drills. But also specific SAR techniques and equipment. So we have things like a portable salvage pump that can shift about 1m³ in 1-2minutes, line throwing rockets, crane launched daughter craft for shore search, breeches buoy etc. Most of the crew have also done basic medical training, things like CPR, giving oxygen or entonox, inserting airways, bag valve mask, tourniquets, combat bandages, etc. We work in close coordination with the coastguard helicopter and with land based paramedics. Our boat is pretty specialised, RNLI all weather lifeboats are designed to survive a capsize and self right again afterwards and we have customised diesel engines that can operate upside down at idle power for short periods of time. As such we can go to sea in pretty much any conditions.