East of Esperanza, this is one of the world's best spots for a glow-in-the-dark experience with undersea dinoflagellates. Local operators offer kayak trips or excursions on nonpolluting boats to see the bay's microorganisms, which light up when the water around them is agitated. 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 bay is at its best when there's little or no moonlight; rainy nights are beautiful, too, because raindrops hitting the water produce ricochets that shimmer like diamonds.
Unpaved roads off Rte. 997, Vieques, 00765, Puerto Rico