It's been a few years since my USAF exchange concluded, but as of 2014 there was no meaningful RADALT hold -- and definitely no coupled hover like we have in the Navy. The altitude hold was unreliable at best, and its use wasn't even discussed at the schoolhouse. As it was described to me, the hover coupler system we had was good enough to keep you in an area roughly the size of a football field, but you wouldn't count on it for precision hovering. An upgrade was coming that might have made its way to the fleet by now, and I'd guess that the 33d would be among the first to receive it (being located on an island and all), but even without it, I wouldn't doubt their ability to locate me in an ocean or render assistance to me once they do.