Underwater cameras Canon D20, Nikon AW100, Olympus Tough, and Panasonic DMC-TS3

I'm in the market for a point and shoot underwater camera. I saw some comments on the specs of the D20 that tore into it for having a poor aperture rating. I really don't want the bulk of a camera housing or the price that comes along with buying a $600+ system. I wish there was a review looking at Nikon AW100, Olympus Tough 810, and Panasonic Lumix DMC-TS3, but since there isn't, let me expand...

After reading all the negatives about the D20 from commentators, it seems that going with the Nikon would be a good choice as it has many of the same features and photo ratings, but it costs a little more than $100 less.

The Tough is in a similar boat with the AW100, but I know people that have the more basic versions and really like it.

The Panasonic has a lower price, slightly better aperture at 3.3 v. 3.9 for D20, and it got the best reviews from the underwater camera reviews for 2011 conducted by dpreview.

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