There are only five places on the planet where the high concentration of bioluminescent plankton makes the water glow with blue light at night. Puerto Rico is one of these unique locations where you can have such a surreal experience. The plankton glows year-round, however, the best time to see it is during the new moon when the nights are the darkest. You can choose from up to three bays to plan your kayaking or swimming adventure.
Mosquito Bay
Mosquito Bay on the southern shore of the island of Vieques boasts the highest concentration of dinoflagellates that produce the glow. There are from 1 to 2 million of them in just a gallon of water. The Guinness World Records called it the brightest bioluminescent bay in the world in 2006. Kayaking tours to Mosquito Bay depart from Las Croabas, about one hour drive from San Juan.
On the southwestern coast of the island, you can visit La Parguera Bay, near Lajas, the only bioluminescent bay in Puerto Rico where you'll be allowed to swim and dive. Glass-bottom boats will enhance your experience as you glide through the glowing waters.
Fajardo
Laguna Grande in the Cabezas de San Juan Nature Reserve near Fajardo is the closest bioluminescent location to San Juan and the most popular with tourists. It is also the most interesting trip for a kayaker. The tour starts among mangrove coves, and then kayakers have to go through a narrow and long channel into the lagoon. In addition to kayaking, Cabezas de San Juan Nature Reserve can be explored on foot during a walking tour or by a motorboat.
Practical info
What is the optimal time to view Puerto Rico's bioluminescent bays?
The bioluminescent bays in Puerto Rico are best viewed during the new moon phase, which occurs every 29.5 days. At this time, there is less ambient light, creating better conditions for the bioluminescent plankton to shine their brightest. For optimal sightseeing, it is recommended to visit between October and February, when there is typically less rainfall, resulting in clearer water. Show more
Where are the three locations to kayak or swim in Puerto Rico?
There are three major sites for kayaking or swimming in Puerto Rico's bioluminescent bays: Mosquito Bay, situated on the southern shore of Vieques island; La Parguera Bay, located on the southwestern coast of the island; and Laguna Grande, found in the Cabezas de San Juan Nature Reserve, near Fajardo. While Mosquito Bay has the densest concentration of plankton, La Parguera Bay allows swimming, and Laguna Grande is the most easily accessible from San Juan. Show more
What is the estimated amount of dinoflagellates found in a gallon of water in Mosquito Bay?
Mosquito Bay in Puerto Rico boasts the brightest bioluminescent bay in the world, with approximately one to two million dinoflagellates present in just one gallon of water. The bioluminescent plankton create a spectacular blue light display, making it a popular spot for night kayaking tours that depart from Las Croabas, situated about an hour's drive from San Juan. Show more
Is it possible to swim in La Parguera Bay, Puerto Rico?
Yes, you can swim and dive in Puerto Rico's only bioluminescent bay that allows swimming, La Parguera Bay in Lajas. Visitors can experience the surreal beauty of bioluminescent plankton while swimming in the blue light-filled waters. Glass-bottom boat tours are also an option, providing a unique perspective of the natural wonder from above. Show more
What other modes of exploration can be enjoyed at Cabezas de San Juan Nature Reserve, besides kayaking?
In addition to kayaking at Laguna Grande, Cabezas de San Juan Nature Reserve offers walking tours and motorboat rides. The reserve's diverse flora and fauna species can be observed during guided tours, highlighting the area's unique wildlife and natural wonders. Walking or boating through the reserve is an excellent way to appreciate Puerto Rico’s natural heritage while surrounded by peaceful surroundings. Show more
