When is the best time to see bioluminescence in the Caribbean?

The best time to see Caribbean bioluminescence is the five nights around a new moon, between May and December. Dinoflagellate populations — the single-celled organisms that produce the blue-green glow — peak in warm water (above 78°F) and bloom strongest in calm, organic-rich bays. Mosquito Bay on Vieques (Puerto Rico) reads brightest in the Guinness world record entry, and the Luminous Lagoon in Jamaica runs a close second. Brightness drops sharply near a full moon — ambient light washes out the glow. Heavy rain in the watershed days before a visit also kills clarity. October and November typically deliver the most predictable conditions in Puerto Rico. A yacht parked offshore lets guests dinghy in at peak darkness without competing with land-based tour groups. Noctourism timing notes map the bio-bay calendar.