I upgraded to the 7D as well from a 40D. Was looking at the 60D but I didn't like the plastic housing plus the downgrade in FPS. 40D = 6.5 fps, 60D = 5.3 fps, 7D = 8 fps. That was really the breaking point for me. The FPS.
I would pick a 40D over a 60D because of the metal alloy body and the fps. Unless of course you want to shoot video. But, getting to the water housing...if you get a good one you should have no worries at all, as long as you take care of it. They cost about the same as your camera and a bit more...but totally worth it if you really want to shoot in the H2o. I had one with my 40D....But, rarely used it. When there's waves I rather surf then shoot.
So total waste of money for me.
That was my same downfall. Originally I took up photography to shoot surfers. That was the reason I got a 7D rather than a 5D, but every time there was some kind of wave. I was out in the line up instead...
I leave it as is. From what I have seen most fisheye water shots normally don't look super distorted because your shooting something already round (if your shooting emptys). now if you have someone upclose in the barrel that might is a little different but normally not a big issue, at least for me.
Sorry if I'm too late in replying to your post... Shooting from the water is a blast and will keep you super fit. I've been water shooting for 15 years and have shot with most of the major makers housings- Auquatech, SPL, Barbish, and Liquid Eye... My recommendation is to go with Liquid Eye... His housings are light, strong, simple to use and by far the most affordable.
Best way to start imo is with a fixed wide angle lens on something like a Canon 7D... get yourself some fins and get out there and shoot your mates. http://www.liquideye-whs.com/
Hope this helps,
Last edited by lex parsimoniae; Jan 25, 2012 at 08:36 AM.