I overheard that one of our core committers is going on a holiday to the Maldives for diving, surfing and swimming. I know that we have another avid diver in our Wicket core team, and that he also makes underwater pictures (I just haven't seen them yet). I've uploaded some of my diving pictures to my flickr account.
We had a small discussion on how to make underwater photographs, and having minor experience myself with some equipment I told them that you need:
- an external underwater flash
- a digital camera with a underwater house
The external flash is necessary because you loose a lot of light when you are already 3 feet under water. In crystal clear water that is not necessarily a problem, but when you are diving at 12 meters (40 feet), the light conditions are not favorable. Of course you could use your own internal flash, but then most photos will look like you're in a blizzard instead. This has to do with the directionality of your flash light in relation to your photo. Head on flash will illuminate all particles between you and the subject. When you flash from a 45 degree angle, the particles most likely not be present as much.
The digital camera is necessary to get instant feedback. You will be underwater for at most 30 minutes or so, and have at most 2-3 dives per day. When you use an analog camera, your learning curve will be severely low. Missing fishes, wrong light, half fishes, too far away fishes etc. All these things can be prevented mostly by the direct, instant feedback digital camera's provide.
As an example I uploaded my second diving trip photo's taken on the fabulous island of Bonaire, using a Canon A-75 digital camera with an external flash. I'll spare you the pictures we took the holiday before in Florida with an analog camera without external flash. Those were pretty pathetic.
I am not an authority on photography, but if you want to take pictures while diving, you'd better buy this minimum equipment.