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Go big or go home.
Seriously if you're just shooting underwater, for the price of one of those you can buy one of these Ikelite housings and an older DSLR (D700 and D800 here) and comprehensively annihilate both in image quality.
The only drawback is, you can't be a bitch and you have to be able to carry it out of the water.
I'm not saying they're bad cameras, because they are not. If you want something pocketable and bulletproof those are the two options right now. The TG-7 has almost DSLR image quality someone posted a thread here a while back taken with one and they were nice.
If you just wanna do underwater photos, the Ikelite is where it's at. Be sure to re-seal it if you get one, it's not a hard job, a fat autistic trucker did all three in this image.