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

Puerto Rico is home to The Brightest Bioluminescent bay in the World and recognized by Guinness World Records in 2006.

Puerto Rico Bioluminescent Bay

Top Rated La Parguera 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… the Bioluminescent Bays of Puerto Rico are as mysterious as a clear night sky.  You may have seen the magical wonder of bioluminescence in movies such as Avatar, Nim’s Island, and Life of Pi.  You can even head to Disney World to be immersed in a world of bioluminescence, but in Puerto Rico, you can experience the REAL magic.

Please Note: 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 to avoid disappointments.

Table of Content – Bioluminescent Bay Puerto Rico Travel Guide

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.  Puerto Rico has bragging rights to being home of “Brightest Bio Bay in the World” by Guiness World Record located on our beautiful little island of Vieques. See below to learn more.

What is Bioluminescence and Does it Occur?

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 called are:  Glowing Beaches, Luminescent, Phosphorescent Bay (Bahía Fosforescénte), Puerto Rico Glowing Water.

Best Bioluminescent Bays in Puerto Rico & Top Rated Tours

A tour of a bioluminescent bay is among Top Five Experiences & Best Things to Do in Puerto Rico. There are few bioluminescent bays in the world, and Puerto Rico was blessed with six, you may read in other places that there are only three but that’s not true, we will not list them for various reasons, the main one is that they are not protected and we are concerned people will flock to them and harm the sensitive ecosystem and balance of the bays.

The following are the most popular and accessible bioluminescent bays in Puerto Rico for tourists, these also have constant higher concentrations of dinoflagellates.

Laguna Grande, Fajardo (East Coast of Puerto Rico)

Most Visited Bioluminescent Bay near San Juan

Laguna Grande - Puerto Rico Bioluminescent Bay

Visitors vacationing in the San Juan and East Coast of Puerto Rico can book a tour to Laguna Grande, part of Cabeza de San Juan Nature Reserve in the town of Fajardo, about 45 minutes from San Juan and 30 minutes from the resorts in Rio Grande.  You have the option to choose a kayak tour or boat tour, your journey will take you through a narrow mangrove canal that leads to the dazzling bioluminescent lagoon.

  • Pros of Laguna Grande Bio Bay – 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:  Some visitors complain that there are too many people during the tour.

Top Rated Laguna Grande Bioluminescent Bay Tours

La Parguera Bioluminescent Bay – Lajas (West Coast of Puerto Rico)

Bright Bioluminescent Bay in the fishing village of La Parguera that allows swimming

Lajas  - Puerto Rico Bioluminescent Bay

There are two bioluminescent bays in La Parguera, for decades it was the main attraction of La Parguera.  Locals also call it the “phosphorescent bay”.  For the past decade, the bays had lost their brightness due to poor development, planning, lack of protection laws, and enforcement of rules.  Perhaps the long break from visitors to the bioluminescent bay helped the bay heal, increasing the dinoflagellates and brightness.  New tour operators are using smaller boats and taking visitors that are mostly vacationing on the west coast of Puerto Rico and we are hearing rave reviews.  Unlike Laguna Grande in Fajardo, the tour will be less crowded and relaxed since the west coast receives fewer tourists in the high season.  Some tour guides offer kayak tours to the best spots where bioluminescence is brighter and boats have no access. 

  • Pros of Lajas Bioluminescent Bays – Fantastic attractions in Lajas and nearby so you can enjoy a great day trip.   Lajas Bio Bay is a more intimate experience, with no crowds.  Tours cost less if you’re in the Lajas and west coast area by choosing this tour
  • Cons:  Distance from San Juan / Metro Area is 2 hours (but the day trip is wonderful, see itinerary below). 

Itinerary Suggestion:  We highly recommend you go to Puerto Rico’s west coast early and enjoy more of the local attractions such as Gilligan’s Island, Los Morrillos Lighthouse area, and Playa Sucia / La Playuela in Cabo Rojo.  The bioluminescent bay will be the perfect ending to your day of exploring the west.  This tour offers a great itinerary. 

Top Rated Lajas Bioluminescent Bay Tours

Local - From Lajas

From San Juan

Mosquito Bay / Puerto Mosquito – Vieques (Island of Puerto Rico off the East Coast)

The Brightest Bioluminescent Bay in Puerto Rico and The World

Bioluminescent Bay - Puerto Rico - Best Bioluminescent Bays in Puerto Rico Guide

We saved the best for last… the best and brightest Bahia Bioluminiscente, Mosquito Bay 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 is it is indeed a magical experience that no pictures or video can truly capture.  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.  Residents of Vieques and those that have experienced the magical brightness of Mosquito Bay were tremendously 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.

  • Pros: Everything, the entire experience is wonderful.  Being in Vieques, a sleepy, pristine, and alluring island with the best beaches in Puerto Rico, and ending the day with the brightest bioluminescent bay in the world.  No crowds on the tour.
  • Cons:  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.  See tours below.

Top Rated Vieques
Bioluminescent Bay Tours

Brightest Bio Bay in the World by Guiness World Record

August 4, 2008 / Guinness Book of World Records 2008 – Living Light

“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.”

Videos of Bioluminescence

Best Bioluminescent Bay Combination Tours

You may wish to consider booking a combination tour to make the most of your precious vacation time and budget.

Laguna Grande Bioluminescent Lagoon

El Yunque Rainforest & Laguna Grande Bioluminescent Bay – Two of the best attractions in one tour.

Lajas Bioluminescent Bay

Cayo Caracoles & La Parguera Bioluminescent Bay – Even if you’re staying in the San Juan / Metro Area, the bioluminescent bay in Lajas is worth the driving time, with fewer crowds, more intimate setting, bioluminescence is brighter while experiencing a less touristy and authentic fishing village.  You may end up coming back to Puerto Rico in order to see more of the west coast, many visitors do.

Lajas Bioluminescent Bay

A Day on the West Coast & Bioluminescent Bay – We love the west coast and this tour hits the colorful town of Yauco, the Cabo Rojo Lighthouse which is the most scenic spot on the island of Puerto Rico and end the day at the Bioluminescent Bay.  With a car rental, you can do it on your own and book this tour for the bioluminescent bay.

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

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

Tours Visitors Love in Puerto Rico