Exploring Laguna Grande, the bio bay in Fajardo

Bioluminescent Bay Laguna Grande in Las Croabas is a one of a kind ecosystem situated along Puerto Rico’s northeastern city of Fajardo. It is the second best-kept bioluminescent bay in Puerto Rico after Mosquito Bay. Visiting a bio bay is by far the most mystifying experience of the island.

Laguna Grande, also called “The big Lagoon” was first spotted by the Spanish in the seventeenth century when they stumbled upon the “devil” glowing water reservoir. They made an effort to prevent the water from the lagoon from entering the ocean. Luckily, by shrinking the outflow from the bay, they aided in luminescence increase.

The uniqueness of bio bay waters consists of its oceanic residents which can light up in the dark. Bioluminescence is genuinely a special occurrence of fragile nature’s ecosystem. The luminescence happens all over the earth, yet only a handful of places are categorized as bio bays. Most of them are at high risk of vanishing because of extensive urban intervention and deficiency of ecological regulations. Fortunately, the bioluminescent bay in Fajardo, Puerto Rico is in good shape featuring great night scenery. Go and check it yourself with a bio bay tour

There are many strict requirements essential for the eco-community of luminescent microorganisms, named dinoflagellates, to remain alive and active. The mangrove trees surrounding bio bay supply various nutrients and minerals from roots and decomposed foliage. A narrow-sized canal connecting Laguna Grande bio bay with the ocean influences the microclimate and temperature within the lagoon. Any transformations of the canal causing it to be deeper, shallower, wider, etc may destroy a bioluminescent bay.

One more pernicious factor for Fajardo lagoon’s vitality is city-wide development linked to increasing levels of air, soil, and water pollution. Year 2015, in an attempt to keep the vulnerable bio bay active and alive, the DNER (Department of Natural and Environmental Resources) of Puerto Rico prohibited swimming in the bioluminescent bay. Since then, there is also a daily limit on the total number of people that could paddle into the bay.

Classic kayak tour on the bio bay



Your guide will give you a safety briefing about kayaking on the bio bay


Get Ready

Pack your stuff, put your safety jacket on and get ready to go!


Let’s Paddle

Once you are comfortably seated on your kayak, it’s time to paddle


Discover the Bio Bay

It’s time to enjoy this unique moment on the bioluminescent bay


Back on Land

One hour spent on the bio bay we are back on land. Full of memories 🙂


Best bio bay tours in Fajardo

Puerto Rico Bio Bay Tours LLC

Since 1997 this company is offering bio bay tours in Fajardo. Regarding their reviews, it seems you can’t be disappointed going with them. 55$ per adult they will charge you the same for a child above +6. They have two departures times 6 pm and 8 pm and the tour lasts 3 hours.

Kayaking Puerto Rico

Created in 2007 this company is offering a combo, Rain Forest and Bio Bay Tour on the same day for 149$ per person. Speaking about their classic bio bay tour on Laguna Grande the price is 55$. Two departure times are 6:30 pm and 8:30 pm and the tour lasts 2 hours only.

Yokahu Kayaks Trips

Less Known than the two first companies on this list, Yokahu Kayaks Trips seem to be a bit cheaper too. 48$ for a 2 hours bio bay tour and 115$ for a combo Bio bay and Yunke tour on the same day. Those prices apply to adults and children above 6 years old.

Eco Adventures Kayaks

A family business that claims to be involved in beach clean-ups. They are offering the classic 2 hours bio bay tour in Fajardo for 48$ per adult above 5 years old. Their second tour is a combo bio bay in Laguna Grande and Rain Forest for 140$ per adult, with transportation included.