Great choice for a dive destination! The shallower reefs got pretty beat up from Wilma last year, but I was there in December and its still a
very fishy place. If you're into fish watching, pick up Paul Humann and Ned DeLoach's book
Caribbean Reef Fish Identification to learn about and recognize the fishes that will keep you company on your dives.
Because Coz is all drift diving, divers have a tendency to blow by the reef like freight trains. If the current's not too wild, and you and your buddy are pretty shallow (you'll burn through a tank of air too fast if you do this deep), occasionally turn and fin into the current to hold a steady position on the reef. Just hover and observe the amazing life all around you. Be sure and let your DM know this is what you plan on dong. Your DM may get a bit fussy if you leave the group and don't let him/her know ahead of time.
I'd also recommend you stop by Aqua Safari dive shop on the main drag next to McDonald's and ask for Sheryl Shea. She is the local
R.E.E.F. fish ID expert and regularly offers fish ID classes/dives.
Be sure to look under ledges and in little holes for the illusive Spendid Toadfish -- found only in Cozumel's waters. And remember to take along a safety sausage. No diver should ever enter the ocean without one -- especially when drift diving.
The Cozumelenos are wonderful people. The food is terrific at the many little restaraunts off the main drag. This post makes me miss the great pico de gallo -- I ate a gallon of it in a week! If you try to speak a little Spanish, the locals will go the extra mile for you everytime.
Dive safe and amaze us with a glowing trip report when you get back!