Laguna Grande
Laguna Grande, Fajardo, PR, 00738
Laguna Grande is one of only three places in Puerto Rico where bioluminescent plankton is consistently found. During the day, this mangrove-lined lagoon in Fajardo looks like others along the tropical Puerto Rican coastline. But come nightfall, the bioluminescent pool glows fluorescent thanks to pyrodinium bahamense, microscopic plankton that thrive in its shallow Caribbean waters and glow when disturbed.
The basics
Visitors can set the water aglow and create a trail of light with every stroke of their paddles during guided nighttime bio bay kayaking tours. Laguna Grande tours are usually offered around the cycles of the moon, timed to the darkest nights. Some tours also combine kayaking with an afternoon nature walk to La Mina Falls in the nearby El Yunque National Park.
There are only a handful of places in the world where bioluminescent plankton is consistently found, three of which are in Puerto Rico. In addition to the Laguna Grande bioluminescent bay, this natural phenomenon exists in Bioluminescent Bay (Mosquito Bay) on Vieques Island and the bay at La Parguera. Laguna Grande in Fajardo is surrounded by a red mangrove forest, native to the surrounding El Yunque rainforest and a source of vitamin B12 to the marine plankton.
Things to know before you go
Kayak tours typically navigate through a tunnel of mangrove trees before reaching the glowing waters.
Swimming in this bio bay in Puerto Rico is not allowed; you can swim and snorkel in the bay at La Parguera.
Guides will sometimes bring a cover so that the tour group can observe the bioluminescence in complete darkness without starlight.
You do not need Laguna Grande tickets to access the bay.
How to get there
Laguna Grande is located in the Las Cabezas de San Juan Nature Reserve, just off the shores of Fajardo, Puerto Rico, and about 40 miles (65 kilometers) or an hour’s drive east of Old San Juan. Tours typically depart from San Juan or Luquillo, which is 9 miles (15 kilometers) away.
When to get there
Kayaking trips frequently set out in the early evening around sunset, launching from Las Cabezas with a tour guide or instructor. The best time to experience the bioluminescent bay is when the sky is especially dark due to little or no moonlight, so try to book your tour around a new moon and avoid days surrounding a full moon.
El Yunque Rainforest
Sometimes coupled with a guided tour of the Fajardo bio bay, a visit to El Yunque National Park is a must-do for nature lovers visiting Puerto Rico. It is the only tropical rainforest in the United States Forest Service and features well-defined walking trails, lush landscapes, and plenty of wildlife such as the Puerto Rican parrot and the Coqui frog.
Ways to explore
Visitors can set Laguna Grande’s water aglow and create a trail of light with every stroke of their paddles during guided nighttime bio bay kayaking tours. Laguna Grande tours are usually offered around the cycles of the moon, timed to the darkest nights. Some tours also combine kayaking with an afternoon nature walk to La Mina Falls in the nearby El Yunque National Park. Kayak tours typically navigate along the access channel through a tunnel of mangrove trees before reaching the glowing waters. Guides will sometimes bring a tarp so that the tour group can observe the bioluminescence in complete darkness without starlight.
Accessibility
Some tours to Laguna Grande are accessible to wheelchair users.
Age limits
None, though tours generally require that participants know how to swim
What to pack
Bug repellent, water bottle, waterproof pouch for phone and wallet, camera for night photos
What to wear
Water shoes, shorts or a swimsuit (to wade into the water when boarding your kayak)
Not allowed
Swimming in the lagoon, leaving trash or other waste in the reserve
Amenities
Most tours include kayaking gear, life vests, and tarps to block light.
Address
Laguna Grande is located in the Las Cabezas de San Juan Nature Reserve, just off the shores of Fajardo, Puerto Rico, and about 40 miles (65 kilometers) east of Old San Juan. Tours typically depart from San Juan or Luquillo, which is 9 miles (15 kilometers) away.
Driving
If you’re driving to Laguna Grande from San Juan, take Highway 3E about an hour east towards Fajardo. Park at Kayak Village—where the boat tour operator offices are clustered—in Las Croabas at the mouth of the channel that leads to the lagoon. There is free parking at the entrance to the nature reserve.
Public transportation
Public transportation is not available to Laguna Grande, but many boat and kayak tours include transfers from San Juan.
Best times to visit
By far, the best time to visit Laguna Grande is after nightfall when the bioluminescent effect is visible. Choose a night with cloud coverage or a new moon for the darkest viewing conditions.
Best days to visit
This popular attraction can get crowded with kayak and boat tours on the weekends and holidays. Choose an evening tour during the week to avoid “boat jams” along the access canal.
Best months to visit
Visit from December to mid-April for the warmest temperatures and least rainfall, ideal for spotting Laguna Grande’s bioluminescence.
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