Fodor's Expert Review Puerto Mosquito Bioluminescent Bay

East of Esperanza, Puerto Mosquito is one of the world's best spots for a glow-in-the-dark experience with undersea dinoflagellates—microorganisms that light up when the water around them is agitated. Local operators offer kayak trips or excursions on nonpolluting boats to see the bay's light show. Look behind your boat at the twinkling wake. Even the fish that swim through and jump from the water bear an eerie glow. The high concentration of dinoflagellates sets the bay apart from other spots (including in Puerto Rico) that are home to these microorganisms. The experience is best when there's little or no moonlight; rainy nights are beautiful, too, because drops hitting the water produce ricochets that shimmer like diamonds. Note that licensed operators are prohibited from leading tours on the day before, during, and after a full moon.