I second the recommendation of Blue XT~Sea Diving. Christi runs a great operation in Coz. Fast boats, great DMs and a great captain. Once they see that you're comfortable in the water and can negotiate the currents without any problems, they pretty much let you run your dives and do their best to find things for you to photograph or just appreciate. A bunch of photographer and videographer friends and I dove with them last year, and we all came back with lots of great images and clips. The only drawback is that Christi's boat, Shamu, has no room on it for camera tanks or rinse buckets. We all just compensated by keeping our cameras covered with damp towels during surface intervals. The boat crews were very careful with our cameras onboard, making sure that tanks and other heavy items posed no threat, and handling them carefully.
I just recently got back from a long weekend at the Scuba Club. On the boat dives, I had no problems stopping to take pictures, but I was always the straggler who brought up the rear. Also, if a shot was going to require me to wait for an animal to move somewhere or get into a certain position, or if I was going to have to do a lot of bracketing or strobe movement, I wouldn't have time to set it up. That said, the boats all have camera rinse tanks or buckets, and I never had a problem finding a relatively dry spot on the boat to change out batteries and memory cards when necessary. The shore diving in front of the Scuba Club provides lots of opportunities for great shots, too, and the entry and exits are very camera friendly.