They sell the disposable cameras in the gift shop. I would suggest, as Surfhary has, to bring your own. I brought one that my love dropped on the hotel room floor and broke the waterproof case, so I had to buy one from CTI. It was quite pricey... approx. $20?
I second the GoPro!. Just make sure you purchase the dive shell for it otherwise your pictures will be blurry. Also for the best coloring
buy a red filter for the lens. It will give a much more natural color to your pictures.