My girlfriend and I just got back from a week in Cozumel. She doesn't dive so we did some snorkeling. During one of the snorkeling trips we got to play with an underwater camera, and this is what we came up with.
http://www.youtube.com/watch?v=3tYfk27tJmo
http://www.youtube.com/watch?v=3tYfk27tJmo