You should also check out
Cozumel Cruise Excursions they sell Nachi Cocom Beach club, its truly the best beach in Cozumel and they have tons of add ons from wave runners, snorkeling,diving, massages, parasailing or just the AI package with top notch drinks ( not cheapy brands) and you can order off the menu ( included) rather then get food from a buffet thats been sitting in the sun for hours breeding bacteria:-)