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.

Puerto Rico Bioluminescent Bay

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.

Puerto Rico Bioluminescent Bay Guide

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

Bioluminescent Bays in Puerto Rico by Location

Tours to Bioluminescent Bays


Planning Tips & Need to Know Facts

What is Bioluminescence and How Does it Occur?

Laguna Grande Bioluminescent Lagoon - Fajardo, Puerto Rico - Tours

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.

Best Bioluminescent Bays & Lagoon in Puerto Rico

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.

Mosquito Bay / Puerto Mosquito

Vieques (Island of Puerto Rico off the East Coast)
Bioluminescent Bay - Puerto Rico - Best Bioluminescent Bays in Puerto Rico Guide

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 ViequesDon’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

+ 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.”


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.”

Top Rated Vieques Bioluminescent Bay Tours

Laguna Grande (Lagoon)

Fajardo, (East Coast of Puerto Rico)

Laguna Grande - Puerto Rico Bioluminescent Bay

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.

Las Croabas meet up point for Laguna Grande Bioluminescent Lagoon in Fajardo, Puerto Rico

+ 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 Juan45 minutes from tourist areas to Fajardo.  See the tours below that offer transportation from San Juan.

From Rio Grande30 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

La Parguera Bioluminescent Bay

Lajas (West Coast of Puerto Rico)

Lajas  - Puerto Rico Bioluminescent Bay

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 tourLajas 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

Tours - Bioluminescent Bays & Lagoon

Fajardo, La Parguera & Vieques - Puerto Rico

Vieques Bioluminescent Bay Tours

If you wish to experience Mosquito Bay, you’ll have to spend the night in Vieques.  We recommend you spend two nights in Vieques, explore the stunning coastline and go snorkeling.

Local - FROM Vieques

Laguna Grande Bioluminescent Lagoon Tours

Local - FROM Fajardo

FROM Isla Verde

FROM Luquillo

FROM Rio Grande

FROM San Juan

La Parguera Bioluminescent Bay Tours

Local - FROM Lajas

FROM San Juan

Combination Tours

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

A Day on the West Coast & Bioluminescent Bay – We love the west coast, and we are confident you will too.  This tour hits the colorful town of Yauco, the Cabo Rojo Lighthouse, and ends the day at the Bioluminescent Bay.

El Yunque Fun & Laguna Grande Bioluminescent Lagoon

Videos of Bioluminescence

Tips & Need to Know Facts for the Best Experience

Bioluminescent Bays - Puerto Rico

How 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.

What to Wear during a Bioluminescent Bay Tour

Please wear comfortable clothing, long sleeve beach shirts are best to protect you from mosquito bites.

Check for Conditions Before your Tour

A few days before your scheduled tour, call your tour guide and ask about conditions, rain, tides, and temperatures that can have an effect on bioluminescence.

Movie Clips of Bioluminescence

Map - Bioluminescent Bays & Lagoon in Puerto Rico

Tours Visitors Love in Puerto Rico

Puerto Rico  ⏐ Things to Do in Puerto Rico ⏐  Puerto Rico Bioluminescent Bays