That's what I thought Echo which is why I posted the thread. Either there aren't many readers of that ilk or they're too modest. One possible explanation, in my time aircrew were ineligible for MR due to injury risks and, presumably, because MR was there to rescue them in the first place if they came to grief.
One slightly amusing story from my own stock. One August Sunday as team Kilo is departing Arrochar after a glorious weekend in the hills someone spots some sort of commotion in the water whilst driving along the shores of Loch Long. Transport all stops for a better look, turns out to be some sort of small whale in the loch. However, of more interest was the two female scuba divers changing to go into the water. They were behind some bushes, but from where the team had stopped on a higher road we had a grandstand view of them stripping off before slipping into their wetsuits (and the carpets most definitely matched the curtains, in both instances !). The entire team kept quiet until the dressing was complete whereupon a very appreciative chorus of whistles and applause rang out. No shrinking violets these two, they turned and gave us all a bow before seting off into the water, flippers and snorkels in hand. How they'd missed a three tonner, 2 x LWB & 2 x SWB Landrovers pulling up we never worked out.
ps Echo, why have you put "voluntary" in inverted commas, do you know of anyone who did it "involuntarily?"