Do you want to do more video or still photos?
My parents bought me an Olympus waterproof camera, I returned it and got a Hero2. I use it for diving, and it has some great quality if you're in clear water or near the surface around here in NE. (The light definitely gets washed out the deeper you go and you get green wash pretty noticeable with the gopro footage. I have had the camera at 100fsw and it provides good picture as long as there is light)
I you're doing stills, get something other than a gopro. I've seen some good pictures on gopro's website, and granted I haven't really done much still photography with it, but I've yet to see good quality pictures come from my Hero2.