Byron777
ok sick one nice, you will be stoked with that and good to get you started!
short ciruit amy
well there are two options mainly, either buy a small instamtic point and shoot which is completely sealed and water proof but they are very limited in what they can do. You can also buy one one of those powershot camera and buy a casing for it with full control, but then also leaves you limited to lens etc yet more control then the instamtic. after that would be a normal DSLR camera which you can get custom housings made for the camera bodies and ports according to the lenses you use which are very pricey!
Instamtic - Cheapest and good for random fun, swimming, snorkeling, spashing around in the waves what not
sightly better model with housing - more control and better quality and functionality, more of the same features above
custom housing - good for all the above and much much more, from surfing to underwater shoots etc.
hope this helps
mark