Bioluminescent Bay (also known as bio bay) of Laguna Grande near Fajardo is one of Puerto Rico’s most popular attractions in an hour proximity to San Juan. The luminescence of water is caused by dinoflagellates, marine plankton micro-organisms that emit a neon green and blue glow when water is agitated. Dinoflagellates are extremely sensitive and responsive to conditions such as amount of salt in water (mangrove trees surrounding the bay increase salinity level stimulating the growth of glowing organisms), temperature and depth of water, pollution, etc. All of the factors make bio bay a unique and fragile eco-system.

bioluminescent bay Puerto Rico

Mysterious light is a simple chemical reaction caused by disturbed organisms that respond by producing light accumulated during the day. Therefore the best sight of bioluminescence follows a sunny day. The optimum time to experience the glowing bio bay water phenomenon, also known as phosphorescence of the sea, is at dusk. However, the conditions may be deteriorated by moonlight and excessive surrounding light pollution. While kayaking with a full moon is an unforgettable adventure, it’s not the greatest time to see the radiance of Bioluminescent Bay Puerto Rico. Plan ahead and check the moon phases. Moonlight is the brightest during the first six days before a full moon. Generally, the darker sky, the better the viewing conditions as neon glare becomes more visible.

If you’re in Puerto Rico only for a few days and the moon is not in a favorable phase, kayak tour companies carry a non-transparent cloth to cover the moonlight so the visitors can experience the nature’s most magical phenomenon – bio bay in Puerto Rico.

Since most of the tours take place during the night, between 6 and 10 p.m. and the way to the lagoon lies through the mangroves brush with abundance of mosquitoes, you should always protect yourself with an insect repellent. Please note, that bioluminescence is extremely hard to photograph unless you have a professional camera with high ISO. It’s highly recommended to avoid bringing any electronic equipment without underwater housing as kayaks can flip over. Many tour companies will assist with taking pictures before leaving the starting point.

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