I was a USAF Pararescueman for over 9 years, 4+ years active duty, and 5 years in the USAF Reserves as a PJ. Diving is a part of what pararescue does, and so we needed to qualify by going through the US Navy School for Underwater Swimmers. Now, pararescue uses either the Navy or the Army Special Forces school for diving, I believe. We combined parachuting and diving, and were part of the Apollo recovery teams too. Sometimes, diving was involved in rendering aid, sometimes in body recovery. Sometimes it was a surface recovery/rescue situation, and sometimes a diving recovery of a parachute or spacecraft/bundle. Any more it's called "Special Tactics," and you can see more at:
http://www.specialtactics.com/index.html
The enclosed photo is of a PJ jumping into the water at White Beach, Okinawa sometime in 1968. We were using a 35 foot diameter, parabolic canopy, with an oval cut in the back for forward speed. It was manouvered by use of "slip risers." These were special risers with a fork in them, which was pulled after the 'chute opened. By slipping the risers in opposite directions, the oval was distorted, which jetted the air unevenly and turned the 'chute. He is wearing twin 42 ft3 tanks, with a single-hose regulator (no SPG in those days; we used the "J" reserve). If you look closely, you will see that he is holding one riser group in his right hand. He has unclipped the Capwell Release, and will let go of the riser group as he hits the water. This collapses the canopy, and prevents him from being dragged through the water in a high wind situation. In the background is the two-man life raft which was our target.
This kind of jump is no longer done, as they have gone to HALO jumping (high altitude-low opening) free-fall jumping with parawings (rectangular parachutes which are very, very manouverable).
SeaRat