Nice thinking SkyDriller, but I'm afraid the reality just isn't that clear cut.
I'm afraid wrist-worn PLB's that are provided by most oil companies now, have been viewed by aircrew and particularly SAR crews, as a complete waste of time. Their range is barely a mile or so, hence there effectiveness is questionable.
From a pilots point of view, they keep going off accidentally in the cabin, forcing us to return to base and get the erroneous transmission switched off. In the aircraft, both pilots are wearing a high powered 'ELT' transmitter fitted in their life jackets, and the aircraft has a beacon as well, automatically deployed and able to be picked up by satellite. This is so far and above anything that the wrist watch PLB's can do.
Now we find that the PLB's are not simply a pain and a bit of a waste of time - They are actually counter productive to safety. Their signals are blocking out the main transmitter and forcing it to switch off - Hence when the RAF arrived to trace the downed Etap aircraft, they couldn't pick up any signals at all.
Trust me - As a pilot who cares about all his passengers, those bloody wrist watches are worse than useless and will endanger lives rather than save them. Wrist watches are available but I've never seen a pilot wearing one !! That must say something, and personally I'm glad that at last someone has found good reason to get rid of those things.