I am a diver as well. Using a Nikonos in the Caymens at 120 feet. Novigator is right,in deep shots you would need a full tilt rig. However, in a pool or down to 5-7 feet,the throw aways are hard to beat. I did notice I had better luck not trying to shoot through my dive mask. Did better holing the camera a foot away and aiming from there.
Look at Paul Crozier's homepage. I took the underwater shots there. Most of my pictures were just below the surface anyway. The colors don't shift and generally brighter.
One shot I took from underneath a sub's 6 o clock you could see fish around the Blue Back of Jeff Portious's boat, the sky above,the trees in the background,and Jeff holding the transmitter! The ones that came out best though,you could not be sure if it was not a submurged shot of the real thing! Jeff and Paul did fine jobs on their kits.
I took my camera down to the local HEB, a grocery store chain here in texas.Told them I did not want photographs,on the cd. One hour later, majic ! Not bad for 6 dollar processing.
It was great fun.
I will add a few to my home page for a while for you to compare to.
SubCommittee Vice President 2006-2008
Author-Russian Submarines, Guardians of the Motherland
Member-Saint Petersburg Russia Submarine Club