Desecheo Island

Desecheo Island is an uninhabited island in the Mona Passage off Mayagüez, managed as a U.S. Fish & Wildlife refuge. Old military ordnance keeps the land closed, so all the activity is in the surrounding water, reached only by boat. Divers and snorkelers find open-ocean fish and visibility of 80–100 ft, with sharks, rays and turtles among the sightings.

The crossing is most reliable from November to April, when the Mona Passage is calm enough to make the trip. Day trips depart from Rincón and Aguadilla.