If warranty is not an issue, I would suggest checking out Ebay for starters. This will give you an opportunity to shop around for used cameras that might fit your needs.
I currently shoot with a Canon Powershot A80 (4 megapixel) with uw housing. I have had minimal issues with stills or video on this camera. Another member has the A85 which is supposed to have an UW setting. Setting the white balance on any digital still camera will help issues in lakes or the ocean as needed. The pics in my profile are a bit green because I did not set the white balance.