have you though about getting and camera/underwater housing? It depends what you want it for,if its diving then you will need a underwater housing as most underwater cameras have a very limited depth. If that is the case i would advise looking for a cheap canon s95 and housing on ebay. This is what i use and gives stunning results especially with a strobe.
However if its just for snorkeling i recommend the olympus tough series as they have very low apertures (f2.0) which is great when trying to take pictures underwater without using the built in flash as this will create backscatter.