About Bioluminescent Bays

Bioluminescent bays are one of the rare natural wonders of the world with only five locations you can experience the vibrant colors in real life. Environmental factors such as excess wind, rain, and pollution can impact the light concentration in the bay making it essential to see now while you can!

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 kayak tours in Puerto Rico from our trusted tour operator partners.


Laguna Grande

Location: Fajardo, Puerto Rico

Details about the bay: This bio bay is the brightest on the main island, giving you plenty of opportunities to see the glowing organisms on a kayak or boat tour. You’ll love paddling the long canal that leads to the lagoon, and then the light show begins! The easiest way to see the water glow is to book one of the tour options below offered at night. It’s always best to take a kayaking tour to learn about the waterways in Puerto Rico. Tour operators are more familiar with the water, and they know how to give you a safe and fun experience.

The only way to see the glowing water of bio bay is to be in a kayak or on a boat at night. (There is no public beach access, sorry you can’t just swim!)


Mosquito Bay

Location: Vieques Island, Puerto Rico

Details about the bay: If you just can’t get enough of Puerto Rico’s bioluminescent bays, visit Mosquito Bay in Vieques to get your fill of the sparkling phenomenon. Vieques is a small island off the east coast of Puerto Rico, and there are only a few options to explore the bay that do not require booking an overnight stay. The beautiful mangroves and abundant wildlife make the journey worth the time and effort!

This bay holds the Guinness World Record as the brightest bio bay in the world, owing to the largest concentration of dinoflagellates and a helpful lack of light pollution that makes the tiny fairy lights stand out even more.

The only way to see the glowing water of bio bay is to be in a kayak or on a boat at night. (There is no public beach access, sorry you can’t just swim!)


La Parguera

Location: Lajas, Puerto Rico

Details about the bay: 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. As the only bio bay that allows swimming, kayaking here comes with a bonus!

You may have heard that La Parguera is the smallest and least bright of Puerto Rico’s bio bays, but that doesn’t mean you should cross it off your list. 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.