Would really recommend some further reading on this site and other forums with regard to the problems some types of PLBs (including some of the ones selected and foisted on the industry so far by O & G companies) cause for the reliable detection and safe rescue of persons in the water.
This jogs my mind into thinking:
a)May be this is why Bristow and PHI maybe against these specific devices.
b)Does anyone know if they maybe advocating other alternative more suitable devices
UCLogic