Can You Swim in the Bio Bay in Puerto Rico? The rules at all three bays.

Which bio bay can you swim in?

None of Puerto Rico's three bio bays is a sure place to swim. Mosquito Bay and Laguna Grande do not allow it, and visitors see both from a kayak or boat. La Parguera is the one bay where the official tourism board describes swimming as allowed, while at least one local operator says it is not and a 2023 government order closed the bay on full-moon nights.

• Mosquito Bay, Vieques: not allowed. The bay is a protected natural reserve.
• Laguna Grande, Fajardo: not allowed. Visitors go on guided kayak tours.
• La Parguera, Lajas: sources disagree. Follow the rule your licensed operator gives you. Our La Parguera tour is a sunset boat tour: you watch the glow from the boat.

Can you swim in the Vieques bio bay?

No. Swimming is not allowed in Mosquito Bay, the bio bay on Vieques. The bay and its mangrove forest are protected by the Vieques Bioluminescent Bay Natural Reserve, and the bay was named a National Natural Landmark in 1980. Visitors see the glow from kayaks or electric boats, never from the water.

According to Wikipedia's entry on Puerto Mosquito, no swimming is allowed in the bay, which is protected by the Vieques Bioluminescent Bay Natural Reserve and was named a National Natural Landmark in 1980. Lonely Planet's guide to Bahía Mosquito, a travel publisher, says the same, and that tours use kayaks or electric motors. The landmark listing appears in a copy of the National Natural Landmarks registry (PDF) on npshistory.com. We found no primary government rule text online to link for this bay.

Can you swim in the Fajardo bio bay?

No. Swimming is not allowed in Laguna Grande, the Fajardo bio bay, which lies inside the Las Cabezas de San Juan nature reserve. Visitors see it on guided kayak tours that paddle a mangrove channel into the lagoon. From your kayak you can move a paddle or your hand through the water and watch it light up blue-green.

According to topuertorico.org, a Puerto Rico travel guide, swimming is not allowed, but kayaking tours give you an up-close experience. We found no primary government rule text online to link for this lagoon. That is exactly how our Fajardo tour works, with a kayak lesson on shore and a guide on the water with you the whole way.

Can you swim in La Parguera bioluminescent bay?

Sources disagree on La Parguera, so here is what each one says. Discover Puerto Rico, the official tourism board, describes La Parguera as the bay where swimming is generally allowed, except on full-moon nights, and says it is not available every night. At least one local operator states that swimming is not allowed there under conservation rules.

The bay, known locally as Bahía Fosforescente, is part of the La Parguera Nature Reserve, managed by Puerto Rico's Department of Natural and Environmental Resources (DRNA). In June 2023, the newspaper Primera Hora reported a DRNA administrative order that closed the bay for three full-moon nights in each lunar cycle, to ease visitor traffic. The tourism board's La Parguera page also advises checking with your tour operator.

Because the sources differ, the rule that applies on your night is the one your licensed operator follows. Ask them before you go. Our La Parguera tour is a sunset boat tour: you watch the glow from the boat.

How close you get to the glow without swimming

Very close. On a kayak the glowing water is an arm's length away: every paddle stroke lights up, and you can trail your hand beside the kayak. A clear kayak lets you watch the glow under you as well. On a boat tour you watch the lagoon light up around the boat, with the whole group together.

• Fajardo: a kayak tour, where you see the glow from your own two-person kayak, with a guide beside you.
• Vieques: a clear-kayak tour on Mosquito Bay, where you see the glow from the kayak and under its clear hull.
• La Parguera: a sunset boat tour, where you watch the glow from the boat after sunset at Caracoles island.

Is the glowing water safe to touch?

Touching the glowing water from a kayak is a normal part of a bio bay tour: on our Fajardo tour, guests move their hands and paddles through Laguna Grande to watch it light up. The health concern scientists describe for Pyrodinium bahamense is about food: Florida's wildlife agency says people are exposed by eating contaminated shellfish or puffer fish.

The Florida Fish and Wildlife Conservation Commission names bivalve shellfish and puffer fish as the seafood involved. In Florida's Indian River Lagoon, researchers identified Pyrodinium bahamense as the likely saxitoxin source in puffer fish poisoning cases from 2002 to 2004. Both sources describe exposure through eating fish and shellfish, which is a different thing from trailing a hand beside your kayak.

Pick a bay, then a dark night

Choose the bay closest to where you are staying: our guide to the best bio bay in Puerto Rico and where the three bays are help with that. Then pick a dark night, because the glow looks strongest when the moon is down. Plan the rest with what to wear and bring and the kayak or boat guide.