The bays’ distinctive, ethereal blue-green glow can be attributed to millions of microorganisms known as dinoflagellates. These little light-emitters make their food by photosynthesis, and it’s this process that creates the glow. We start to see their light as the sky grows dark, but the real magic happens when these microorganisms are agitated by the stroke of a paddle in the water or fingertips trailing below the surface.
With up to one million of these single-cell organisms per gallon of water, the phenomenon has been described as a soft smattering of pixie dust floating through the water. Explore the three different bays and how to see the light glow while on a boat or paddling through the water. This is a can’t miss experience while in Puerto Rico. Whether you like to book in advance or while you’re in-destination, we have the right options for you. We have curated the best bio bay tours in Puerto Rico from our trusted tour operator partners.
Laguna Grande
Location: Fajardo, Puerto Rico
Tour options: Book Kayaking Tours or Combo Packages
About the area: Fajardo is home to the best beaches and watersports in Puerto Rico. Just a quick drive from San Juan you can explore the local beaches, rainforest, and wildlife in the area. To simplify your trip planning, there are combo tours available which will take you through the beaches and rainforest ending with a spectacular kayak experience through the bio bay. If you’d rather keep your day plans open, you can book a night kayak in Laguna Grande to see the water light up at night. This bio bay is the brightest on the main island, giving you plenty of opportunities to see the glowing organisms on a guided kayak tour.
The best way to see the glowing water is to take a kayak tour with an experienced guide. They will provide a history of the area and explain the science behind the magical glowing water.
Browse and book Laguna Grande Kayak Tours and Combo Packages here
Mosquito Bay
Location: Vieques Island, Puerto Rico
Tour options: Book Kayak/Boat Combo Tour leaving from San Juan, Kayak Tour leaving from Vieques
Details about the bay: If you are interested in experiencing an area less frequented by the average tourist, Vieques is a great find. With plenty of restaurant options and activities available, Vieques is a great spot for a day trip or a multi-day trip. The island itself is filled with beautiful architecture, sandy beaches, and is home to Puerto Rico’s brightest bioluminescent bay. The majestic glowing water offers guests a mesmerizing, unforgettable experience.
This bay holds the Guinness World Record as the brightest bio bay in the world, due to the largest concentration of dinoflagellates and a helpful lack of light pollution that makes the tiny fairy lights stand out even more.
To experience this bio bay, explore different kayaking options available on the island or from San Juan.
La Parguera
Location: Lajas, Puerto Rico
Tour options: Book Boat Tours
About the area: La Parguera is a great option for travelers staying on the southwest side of the island, and it’s only two hours from San Juan.
La Parguera is another great option to experience a bio bay, especially if you prefer to visit by boat instead of on a kayak. The dinoflagellate concentration is lower than the other bio bays making the water appear less bright, but at the very least you will enjoy a nice boat ride through the water. If you’re staying in Lajas or the surrounding area, La Parguera offers a chance to see the bioluminescence without traveling far. While it isn’t the best example of a bio bay, it’s still better than not seeing one at all. As a bonus, because this bay is the least visited, tours are often less expensive and easier to book. Also, snorkeling or swimming may be an option depending on the tour operator.