Just what kind of
techniques are you trying to video with your bum sticking in the air?
I've done some video work with the local master's swim team,. I used a video camera with a very wide angle lens and swam along side of them underwater as they swam above, and to the side, of me. At the end of each lap they could review and see how they were doing. I think a wide angle lens is very important so you can get close enough to the diver, yet still get them, and their fin(s), into the frame.
For constant it's a bit tricker around here because of the thermocline. We can have great vis on the surface and at depth, but that middle layer is going to be hazy no matter what you do- unless you're training under ice and then there's no thermocline to worry about. For that we go don and meet the diver right above, or below, and film from there. Sometimes we'll follow them up and you can see the vis go to hell as you pass through and then it gets clear again. Ted put some of this footage together for one of the palooza videos. First, you'll see a diver descend in gorgeous vis, and the next thing you know they are on the bottom swimming through the trees- everything in the middle had to be tossed!
Hopefully that's not an issue where you dive.
Still, get the wide angle lens.
Jon
