6. See the bioluminescent organisms in Vieques, Puerto Rico For a different kind of night life, visit Bio Bay in Vieques. The water luminescence is triggered by oceanic plankton able to generate an emerald green and ultramarine illumination when water is physically disturbed and is only visible at night. Dinoflagellates are incredibly delicate microorganisms and are very sensible to the environment conditions such as balance of salt in the water, local climate, deepness of lagoon, air and water pollution, etc. For that reason, and to preserve this wonder for future generations, the number of tour guides is closely regulated by the Puerto Rican government and emersion into the bay prohibited.