Not sure how much you want to spend but I would just start off with a new point and shoot like my a 720is. I would probably buy one of the new ones that you can put underwater just drop it in the tank and start taking pics. If you buy a SLR like my 40d it gets expensive fast $600.00 just for a macro lens. I find the cheap point and shoots take very good pics and so much easier to use and faster to pick up and start shooting