All this paranoia about SARwatches reads very much like the current paranoia about getting the frequency right for that Mayday call (Closest ATC? Charted ATC freq? 121.5?). Why the angst? Nobody's going to get to you for hours. And did you put in a flight plan so the searchers would at least have the lateral search part sorted out?
Oh, hang on, LB could use "mobile phone location technologies" to send a Whatsapp location. That'll help the searchers.