Got a 210 with GPS - always on me (lifejacket) even if its a very very local trip.
Its the last resort for help ( after DSC HH - also on lifejacket - both attached with lanyards) .
If I ever find myself floating in the water without a boat I'm setting everything off ! I'd be happy to admit defeat at that point !
Interesting comment when we were at Solent CG - they see more false alarms from the Mcmurdo site in Portsmouth - but as soon as they have a fix it poops on thier map screens with the given position which allows them to either react by sending poeple out pronto or calling mcmurdo to let them know, or a land unit to a house - or an MRT to a hill etc ....