First off, bookmark this site. It's really all you need to know if you want to research cameras:
http://www.dpreview.com/Next, in the point-n-shoot market, the two top competitors seem to be the Pentax Optio W* series and the Olympus Stylus *SW series.
I see the two latest cameras are the Pentax Optio W60 and the the Olympus Stylus 1050 SW. I'd use the above website to do a full comparison and review of both those cameras and choose the one that fits your needs.
The last option, for those with the need or want for a better shooting underwater camera is to buy a bigger SLR type camera and stick it in a waterproof housing. Much more expensive, much more bulkier, much faster, but will take a much better photo than the point-n-shoots.
I personally have had both the Pentax and the Olympus cameras. (WPi and the 770SW) Of the two brands, I didn't like the Pentax camera. So far, the Olmypus camera is OK. I think they are both pretty mediocre cameras, as point-n-shoot digital cameras go. But, if you really need/want the waterproofing, your choices are very limited.
Note that you will lack in *some* features if you go the waterproof/water resistant route. These cameras usually lack in speed, memory, focus speed, etc.
Since I am prone to taking a really crappy photo, to get around this I carry my waterproof camera and a much faster FujiFilm in a waterproof type case. On the days it's not wet outside, I'll use the Fuji. On the days that I'm wet, or will get wet, I just suck it up and use the waterproof Olympus.
Since I have drowned two digital cameras, I'm on "camera probation" for pretty much EVER.
I have a nice Canon D10 SLR at home that takes a flawless photo, but I'm not willing to hump that along in a big old bulky Pelican case while on the river.