Watch your skin glimmer like a dim glow stick as you swim and paddle at night in Falmouth’s Glistening Waters Bioluminescent Lagoon, also known as Luminous Lagoon. Luminous lagoons like this one are uncommon, with only about a dozen recorded around the world. Except for stargazing, these bays are nature’s best natural nighttime show.
Puerto Rico and the island of St. Croix in the U.S. Virgin Islands have the Caribbean’s only other bioluminescent bays. Take a few hours one evening to witness such a rare experience at Falmouth.
Bioluminescent Bays are uncommon due to the conditions needed to create them. Most crucial is the heavy concentration of many millions of small micro-organisms called dinoflagellates, which emit a flash of light whenever disturbed. Scientists believe the flash is a defense mechanism to evade and distract threatening predators.
The shallowness of the bay — only between 3 and 8 feet deep — is credited for the lagoon’s brightness. The shallower the water, the easier it is to see the dinoflagellates. The bay’s location is important, too. The Martha Brae River happens to flow into it, creating brackish waters the dinoflagellates seem to flourish in.
Yet no luminous bay is a guaranteed long-term attraction. For unknown reasons, the lights have gone out or severely dimmed at other popular bioluminescent bays.
Tours and swims of the Luminous Lagoon start at sunset when 30-passenger boats depart Falmouth’s Glistening Waters Marina. Tours leave later as well, when it is darker. If you intend to swim, come already dressed for your plunge and with your own towel. When the water glows around the boat as it moves through the water, especially at the stern, everyone on board has a good view.
Unfortunately, photographing the phenomenon is difficult. A video camera with image stabilizer may be best way to capture the experience. Flash photography may be banned because it destroys night vision. Your best images may stay stored in your memory.
Such as when you jumped into the water and had the magical blue-green glow surrounding you. If it rains, so much the better. The entire bay will start to sparkle then.