Hi Chris, there's a small Adventure Park in Cozumel that has a zipline, though it's not the best. Obviously, though, Cozumel snorkeling is fantastic. You might also consider somewhere like Dominica, a small island with both amazing snorkeling and a mountainous, rainforest interior. Rain Forest Adventures Dominica features the highest zip line tour in the southern Caribbean. Soufriere-Scotts Head Bay and Champagne Beach are both popular local spots for snorkeling!