Side 1 is a map of Cozumel, "Island of Peace" in Mexico, one of the best dive and snorkeling locations in the world. Dive sites are named and located on the map. Side 2 is a coral reef creatures identification guide with beautiful illustrations of nearly 100 species. This convenient, waterproof reference is made of rigid, laminated plastic with hole for lanyard. 5.5" x 8.5"