SASless:
The MCA/Bristows and the Royal Airforce do not use "free divers" in the water. The Royal Navy do. From the Crabs and MCA standpoint, we have never needed or considered it necessary to qualify in this manner. Obviously the RN have different requirements. The only time that the crabs could have used this technique would have been to recover Dave Bullock in an accident with a downed American pilot in the Wash Danger Area back in the 70s. In this instance the parachute inflated with Dave and the pilot still attached. Sadly Dave was drowned due to the fact he could not physically release himself and was dragged through the waves for miles. Eventually an American helo (Jolly Green I think) used the free diver technique to grab Dave as he went past and collapse the chute. Following on from this accident the J Knife was "invented" which would allow a Winchman in Dave's predicament to cut himself free.
Regards
Tuck
PS Yes I agree free divers are brave but then all winchmen are!