Listed as vulnerable to extinction, diving or snorkeling with whale sharks is considered by many to be a once-in-a-lifetime experience. The best chance of encountering a whale shark occurs near a full moon, when thousands of grouper and snapper congregate there to spawn. In addition to whale sharks, this reserve also serves as a feeding ground for the rare loggerhead sea turtle.

The Gladden Spit and Silk Caye Marine Reserve sits 26 miles (42 km) from the coast of Placencia. Scuba, snorkeling, and island hopping trips can be arranged on the mainland, and the boat ride takes approximately 1.5 hours from Placencia.