A lot of people tend to think of underwater photography as a thing they're going to have to spend hundreds of dollars just to get started and don't realize there are reltively cost effective cameras available for those who just want to take a few snapshots while they are snorkeling or diving.
We carry the Snap Sights Sports Utility Cam at our shop. It's a basic housed film point and shoot camera. You'll find "underwater" single use cameras that are good to 12/15/30 feet around at a lot of places. These cameras are a bit beefier... they're good to 100 foot depths, so they're great for snorkelers, kayakers, and scuba divers. These specific cameras are quite nice in that they come loaded with 27 shots and are refillable/reusable... you can put another roll of film in when you are done and take them back underwater again. They are also quite nice in that they come with a built in flash, you'll have a chance at taking a picture with good color. Water tends to absorb color, and without a flash the pictures can look dull and bluish. With a flash, you add light back so you get your color back. The flash is really only good to about arm's length or so but it really helps bring back the true color of what you're looking at if you're about 2-3 feet away or so.
These cameras are a fun and reltively inexpensive (we're selling them for $19.99 at our shop) way to try underwater photography and bring home some memories without breaking the bank.