Novice snorkeler--do not worry. You can snorkel off Caye Caulker and be just fine. Didn't go to Mexico Rocks, but went on Seaduced with Elito and he guided the group. In fact, he even held on to one person via life ring who was feeling unsure of her skills. There are life jackets, if you want them, but last week, the snorkeling was easy, no strong currents, etc. The payoff was WORTH IT!!! Lots of coral, lots of fish. My advice is to buy your waterproof cameras in US. You will definitely want more than one!