Puerto Rico ⏐ Things to Do in Puerto Rico ⏐ Puerto Rico Bioluminescent Bays
Puerto Rico is home to The Brightest Bioluminescent bay in the World, recognized by Guinness World Records in 2006.
Save a Spot - 5-Star Bioluminescent Bay Tour
Puerto Rico was blessed with the most bioluminescent bays in the world and the brightest. Water stars, glittering, gleaming life illuminating the bay like a mirror of the cosmos… You may have seen the magical wonder of bioluminescence in movies such as Avatar, Nim’s Island, and Life of Pi. Puerto Rico has bragging rights to being home of “Brightest Bio Bay in the World” according to the Guinness World Record.
Dear Visitors – Although Puerto Rico Bioluminescent Bay is a pretty magical experience, you may encounter some frustrations. A few details make the experience better or worse, depending on your own preferences. For the best experience and brightest conditions, please take a few minutes to read the pros and cons of each bio bay, planning tips, and FAQs below on this page before booking a tour to avoid disappointments.
You could head to Disney to be immersed in the fantasy world of Avatar’s bioluminescence, but in Puerto Rico, for a fraction of the entry ticket, you can have a fantastic vacation and experience the REAL magic.
You’ll glide across the water as day turns to night and surround yourself with the quiet glow of nature’s phosphorescent organisms living in the water, best experienced on a moonless night. This world-class natural wonder is too magical to miss.
Table of Contents – Bioluminescent Bay Puerto Rico – Travel Guide
Learn about this Magical Natural Phenomenon
- What is Bioluminescence and How Does it Occur
Bioluminescent Bays in Puerto Rico by Location
- Mosquito Bay – Vieques, Puerto Rico ⎮ Tours – The brightest bioluminescent bay in Puerto Rico / Guinness World Record for Brightest Bioluminescent Bay in the World
- Laguna Grande – Fajardo, Puerto Rico ⎮ Tours – The most visited bioluminescent bay near San Juan
- La Parguera Bioluminescent Bay – Lajas ⎮ Tours – The only bioluminescent bay where you can swim.
Tours to Bioluminescent Bays
Media
Planning Tips & Need to Know Facts
- How You Can Help Us Protect the Bioluminescent Bays of Puerto Rico
- The Moon Phase & Bioluminescence
- Are you allowed to swim on the bioluminescent tour?
- Should You Take a Kayak or Boat Tour?
- Crowds during Bioluminescent Bay Tours
- What to Wear during a Bioluminescent Bay Tour
- Check for Conditions Before your Tour
Laguna Grande – Fajardo, Puerto Rico
The magical little creatures responsible for this magical experience are named Pyrodinium bahamense, dinoflagellates, fondly called Dinos. The dinos are microscopic organisms, and when they come into contact with anything on the water or sense movement, they light up in bright blue light as a defense mechanism. The more dinos in the water, the brighter the light, and when you dip your hands in the water, it literally looks like tiny stars running down your hands. You’ll see shapes of fish turning blue as they swim alongside your kayak, your kayak paddles will turn the water into magical blue. Again, bioluminescence is best experienced on a moonless night.
There are no “beaches that glow” in Puerto Rico, there are lagoons and protected mangrove bays. The areas that are bioluminescent are best accessed by kayak and boats. Other ways the bioluminescent bays are often called are Glowing Beaches, Luminescent, Phosphorescent Bay (Bahía Fosforescénte) & Glowing Water.
The following are the most popular and accessible bioluminescent bays in Puerto Rico for tourists. These bays and lagoon have high concentrations of dinoflagellates all year round.

The Brightest Bioluminescent Bay in Puerto Rico and The World
The best and brightest Bahia Bioluminiscente, Mosquito Bay is located on the gorgeous island of Vieques. Don’t let the common name, Mosquito Bay, prevent you from experiencing this wonder of nature, you won’t be ravaged by insects. This natural wonder was spooky, unfamiliar, and exotic to the first European explorers. We can only imagine how bright it was centuries ago, but we can assure you that it is indeed a magical experience that no pictures or video can truly capture. Residents of Vieques and those that have experienced the magical brightness of Mosquito Bay were concerned for the bioluminescent bay after Hurricane Maria, to everyone’s surprise, it recovered quickly and it became brighter than ever. Mosquito Bay has the largest concentration of dinoflagellates and when combined with the low light pollution on the island, it is a spectacle on a Moonless / New Moon night.
Mosquito Bay is the most brilliant of the bioluminescent bays in the world and was recognized as such by Guinness World Records in 2006 as The Brightest Bioluminescent bay in the World.
+ Need to Know / Pros & Cons of Vieques Bioluminescent Bay
Pros of Visiting Vieques Bioluminescent Bay
- Everything… the entire experience is wonderful… if you have the time to spend a night in Vieques. Being in Vieques… exploring the undeveloped coastline, having dinner in Esperanza to the glow of the sunset, and ending the day at the bioluminescent day is such a special experience.
- Another benefit is that there are no crowds on tour. If you can’t stay the night in Vieques, we highly recommend you go to the Lajas Bioluminescent Bay, fewer crowds, you are allowed to swim, great sunsets, great food and you can return to your hotel that night.
Cons of Visiting Vieques Bioluminescent Bay
- You’ll have to stay overnight in Vieques, but we don’t see that as a negative if you have the time and budget. We recommend you stay one or two nights, explore the beaches, and experience the magic of Mosquito Bay. You’ll fall in love with Vieques, we certainly do every time we go. See top-rated tours below.
+ Getting to Mosquito Bay in Vieques
From San Juan and tourist areas
- By air – You may take a flight from San Juan Airport, Isla Grande, or Ceiba Airport.
- By ferry from Ceiba – You may drive, take a taxi or private transfer to the Ceiba ferry terminal (see transfers below).
+ Mosquito Bay on the Media
Living Light
August 4, 2008 / Guinness Book of World Records 2008
“The Mosquito Bioluminescent Bay on the Island of Vieques, Puerto Rico is the most bioluminescent in the World. It contains up to 160,000 microscopic dinoflagelates per liter of water.
When agitated, these microscopic organisms (Pyrodinium bahamense or swirling fire) reacts emitting a blue-green light for about a decimal of a second. There are other bioluminescent bays around the island, but the Mosquito Bio Bay is the one that shines with the most intensity, its shallow and small entrance from the sea impedes the waves from washing away the dinoflagellates; and the mangrove trees, with their decomposition process, provides abundant food for the micro-organisms.”
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One of the Most Romantic Places on Earth by Travel & Leisure – by Travel & Leisure
“Illuminated Vieques A guided tour on a motorboat isn’t the way most romantic evenings begin, but once you slip your body into Mosquito Bay, a bioluminescent lagoon off the island of Vieques, you’ll have forgotten the exhaust fumes. Millions of “stars” (actually, they’re microscopic organisms in the water) light up with a stunning blue-white glow, and scatter with every splash you make. Spielberg couldn’t ask for better special effects.”
Go With the Glow!! Is it Magic? by National Geographic (new window)
No, it’s not magic. With each paddle stroke, the girls stir up millions of tiny dinoflagellates (dy-no-FLAH-juh-luhts). When stirred at night, these plantlike life-forms glow beautifully. Each gallon of Mosquito Bay water holds some 750,000 dinoflagellates. Their combined light creates spectacular evening shows.
On the island of Vieques off the coast of Puerto Rico, Mosquito Bay’s dinoflagellates give off their bioluminescent (by-oh-loo-mih-NESS-ent) light from dusk until dawn. “In other parts of the world, bioluminescence is seasonal,” explains Sharon Grasso, a tour guide on Vieques. “But here, the water glows brightly year-round.”
Each night Grasso shows off the natural beauty of the bay. Passengers stare in awe as the tour boat leaves a glittering trail. They dip their hands in the water, leaving greenish-blue trails of their own.
Mosquito Bay’s displays are threatened, however. Bright artificial light from nearby developments can outshine the natural glow. Pollution, destruction of mangrove trees, dredging, land development, and overuse of the bay’s water can kill the fragile dinoflagellates. “We can’t let the lights go out,” says Grasso. “The magic of Mosquito Bay should live on forever.”
Laguna Grande (Bioluminescent Lagoon) as seen from Cabezas de San Juan Lighthouse
Most Visited Bioluminescent Lagoon near San Juan
Laguna Grande is the most visited bioluminescent lagoon in Puerto Rico, located on the east coast, in the town of Fajardo. Tours depart from Las Croabas (pictured below). The best way to experience the lagoon is by kayak where you’ll glide through a mangrove canal leading to the dazzling bioluminescent lagoon.
+ Need to Know Facts / Pros & Cons of Visiting Laguna Grande
Pros of Laguna Grande Bioluminescent Lagoon:
- Closest bioluminescent lagoon to San Juan.
- Some tours combine top attractions like El Yunque so you can make the most of your day and save money.
Cons of Laguna Grande Bioluminescent Lagoon:
- Some visitors complain that there are too many people during the tour. You’ll be kayaking on a mangrove channel. Mangroves are protected, so you won’t be kayaking on a perfectly lined channel, watch for branches. Depending on the number of visitors, it may feel crowded on the way there or back from the lagoon.
- If this is your first time kayaking, you may find the experience challenging, the average tour duration is 2 hours. Depending on the current, and your fitness level, the trip may feel strenuous.
- The channels are dark, and some visitors feel discomfort, especially those without kayaking experience. Tour guides do have flashlights to help along the way. Consider taking a boat ride in La Parguera if you’ll have an issue with kayaking in the dark.
+ Getting to Laguna Grande in Fajardo
From San Juan – 45 minutes from tourist areas to Fajardo. See the tours below that offer transportation from San Juan.
From Rio Grande – 30 minutes from the resort area to Fajardo, some tours offer pick-up.
Top Rated Tours to Laguna Grande
Tours from San Juan
Tours from Fajardo
The only bay where you can jump in and swim located in the fishing village of La Parguera. La Parguera is the best experience overall on the main island with small crowds, great food, live music on weekends, and daytime activities.
Need to Know Facts / Pros & Cons of La Parguera Bioluminescent Bays
Pros of Lajas Bioluminescent Bay
- Fantastic attractions in Lajas and nearby so you can enjoy a great day trip. See the itinerary suggestion below.
- You can swim at this bioluminescent bay making the experience more special.
- Lajas Bio Bay is a more intimate experience, with no crowds.
- Tours cost less if you drive yourself. You can choose from various tour operators once in Lajas costing from $15 – $40 per person. You may also book ahead if you’re in the Lajas and West Coast area by choosing this tour. Lajas is a popular spot for locals on weekends so booking in advance is advised to guarantee a spot.
Cons of La Parguera Bioluminescent Bay
- Distance from San Juan / Metro Area is 2 hours. This will be a full-day trip if you’re traveling from San Juan.
Itinerary Suggestion to La Parguera, Lajas
We highly recommend you go to Puerto Rico’s west coast early and enjoy more of the local attractions. Great places to visit are:
- Caracoles, Cayo Enrique, Sunset & Bioluminescent Bay at La Parguera.
- Los Morrillos Lighthouse area, and Playa Sucia in nearby Cabo Rojo. This tour offers a great itinerary.
The bioluminescent bay will be the perfect ending to your day of exploring the west.
Swim on the Glowing Waters of La Parguera
If you’re staying in the San Juan / Metro Area, the bioluminescent bay in Lajas is worth the drive. You’ll drive along the scenic highway crossing the mountains. Once in La Parguera, you can also enjoy a cultural experience with delicious traditional food, local crafts, and more activities such as exploring the nature reserve made up of mangrove islands and channels where you can admire the scenery, swim, and snorkel. If you’re here on the weekends, you’ll be entertained by live music. Bring comfortable shoes to practice your salsa moves at the lively plazita (small square).
Decades ago, the bioluminescent bay was much brighter, the locals refer to it as “Bahia Fosforescente” (Phosphorecent Bay), big boats with glass bottoms used to take visitors on tours. Due to poor protection laws and/ or not enforced, poor planning, illegal homes on the nature reserve, among other factors, the bay progressively lost its brightness. The break from many visitors has helped the bay heal, increasing the dinoflagellates and brightness. Current tour operators are using smaller boats, during your tour, you’ll only see a few boats. Unlike Laguna Grande in Fajardo, the tour will be less crowded and relaxed since the west coast receives fewer tourists than the San Juan / Metro area.
A trip to La Parguera is sure to entice you to come back to Puerto Rico to explore more of the laid-back and beautiful west coast.
Top Rated Lajas Bioluminescent Bay Tours
FROM Lajas - Local Tour of Bioluminescent Bay
FROM San Juan
Day on the Keys of La Parguera, Sunset & Bioluminescent Bay
The following tour offers a full-day tour to La Parguera from San Juan. Swim on the crystal clear waters of Caracoles, watch the sunset, and end the day swimming in the bioluminescent waters.
The Colorful Yauco, Cabo Rojo & Bioluminescent Bay in Lajas
El Yunque Fun & Laguna Grande Bioluminescent Lagoon
Videos of Bioluminescence
Tips & Need to Know Facts for the Best Experience
Bioluminescent Bays - Puerto RicoHow You Can Help Us Protect the Bioluminescent Bays of Puerto Rico
Although swimming is not allowed, sadly some tour operators allow visitors to get in the water, particularly in the bio bay in Lajas. Please do not wear sunblock lotion, or bug repellants, when in contact with the water, it will harm the delicate balance of the ecosystem. Please consider purchasing natural insect repellent without feet, a much safer alternative both for you and the dinos.
The Moon Phase & Bioluminescence
Be sure to check the moon phase calendar. Bioluminescence is best seen on a moonless night, so the brighter the moon the less bright the lagoon/bioluminescent bay will be. Various tour operators will not run tours on a full moon. Mosquito Bay is so bright, we’ve seen it very bright even in a full moon sky.
Are you allowed to swim on the bioluminescent tour?
Keep in mind that like much of Nature, this biological system is fragile, so no swimming or physical interaction with the bioluminescent organisms is / should be allowed. The bioluminescent bay in Lajas allows swimming, as previously stated please help protect the bays by wearing natural insect repellent.
Should You Take a Kayak or Boat Tour?
- By Kayak – Kayaking tours are the most popular way of touring the bioluminescent bays and lagoon of Puerto Rico. Kayaks allow a more interactive experience with the water, and the flora along the mangrove channels can be more appreciated. The waters are calm along the bay under normal weather conditions requiring average physical ability.
- By Boat – Various tour guides offer tours by small boat. Families with small children should consider a boat tour for the safest conditions. Boat tours are recommended in Lajas since they allow swimming for the ultimate experience. (see below for more information on location and tours).
Crowds during Bioluminescent Bay Tours
If you read reviews from tours, some people complain about crowds during kayak tours. Following are facts to know about the bioluminescent bays and lagoon in Fajardo to help you make the best choice for the most enjoyable experience:
- Laguna Grande in Fajardo is located on the east coast of Puerto Rico, making it the most accessible, receiving the most visitors, since the majority of tourists stay in the San Juan, Isla Verde & Rio Grande resort communities.
- La Parguera Bioluminescent Bay is located southwest of the island. The drive to Lajas from San Juan is about 2 hours, which in our opinion is well worth the drive, the bay is brighter (under optimal conditions), with boat tours are smaller and more intimate with much fewer visitors when compared to Laguna Grande in Fajardo.
Movie Clips of Bioluminescence
Tours Visitors Love in Puerto Rico
Puerto Rico ⏐ Things to Do in Puerto Rico ⏐ Puerto Rico Bioluminescent Bays