Originally Posted by chewy
Thats my point though after been told auto lifejackets are the best its no point floating face up and unconscious with a PLB in your pocket that hasn't gone off.
Chewy I don't think there are any 406 MHz PLBs available with an Auto activation on water option (as opposed to EPIRBs with a "float free" function) - I would guess this is possibly a type approval issue to minimise the number of false alarms. I think there are 121.5 MHz systems that will auto trigger - but these no longer trigger a CG SAR response directly - so someone needs to be looking for you first.
The difference compared to a L/J is if you accidently trigger an auto L/J it costs you about £15 to rearm it and all is well (e.g. if you forget you are wearing it whilst recovering the boat, leave it in the bottom of the boat as Mollers did, or even in a locker). If you accidently trigger a PLB you get a lifeboat/helichopter etc. Whilst in some cases you will be aware you've triggered it and can call the CG to appologise - in the three examples I gave (and they are not exhaustive) you may well not realise its been triggered and have your radio off so not respond to the CG asking whats wrong.
Your chances of survival if unconscious with a PLB in your pocket but not transmitting are still higher with an auto LJ.