This is quite the operation, the housing is HUGE and totally throws off your buoyancy. I'm starting to get the hang of it though.
I started shooting in the pool this weekend. My unlucky subjects were my father, some rubber toys and a teacup. I am using my trusty old Canon AE1 35mm film camera and an underwater housing with a slave flash. After some considerable research, I have settled on using 400 speed color film. Obviously there is nothing artistic about these images, we just went down to do some bracketing and figure out how far the flash would reach (about 8 feet). I have only shot underwater once before, so this has been a fun, somewhat challenging experience. I'm getting more and more excited about getting down there and really shooting with a model and some other objects. Can't wait!