Deb, snorkeling in Cozumel is great, plan time either before or after your dolphin swim to snorkel around the park. Caymen has some really neat snorkeling around old shipwrecks, lots of dive shops on the main street that offer snorkel tours, the snorkeling associated with Sting Ray City isn't all that great. Snorkeling in Jamacia- don't bother, all i got from snorkeling in Jamacia was coral bruises & cuts, the coral is very sharp and just jutts right up at you if you aren't careful. My legs and arms were a mess.