Puerto Rico Bio Bay Swim: Sunset or Late Night Tour

Swim in water that glows when you move through it

A 2-hour boat activity in Puerto Rico where you swim in a bioluminescent bay—one of only five in the world and the only one you can enter—plus a sunset swim at La Parguera's sandbars on the sunset option, or bio bay only on the late-night tour. Guide speaks English and Spanish; children from age 1 welcome. Floaties provided.

The Experience

The boat leaves La Parguera a half hour before sunset on the sunset tour, heading first to the sandbars where you swim and watch the sun drop into the water. After that, the captain takes you to the bio bay for 30 minutes in the water—the part most people come for. When you move through it, the water lights up around your body in a soft blue-green glow. It is bioluminescence, caused by dinoflagellates that react to motion. You can float, kick, wave your arms, and watch the light trail behind every gesture. On the late-night tour during high-demand season, you skip the sunset stop and go straight to the bay.

The boat is described as very nice, and the captain is skilled at finding the best conditions. Floaties are included if you want them. The whole outing takes about two hours from dock to dock. A guide on board speaks English or Spanish, so the commentary and safety briefing come in your language. Children as young as one year old can come along.

You will want to bring a towel and a change of clothes—neither is provided. Snorkeling gear is not part of this tour. The activity involves swimming and moving around in the water, so moderate fitness helps; it is not recommended for travelers with poor cardiovascular health.

What’s included

• Floaties.
• boat transportation to the sandbars and bio bay.
• guide in English or Spanish.
• 30-minute swim in the bioluminescent water.
• sunset swim at La Parguera on the sunset option.

Good to know

Moderate physical levelPets welcomeNot for heart conditions

Operated by Mareaito Charters

Is this one for you?Choose the sunset tour if you want two distinct swims—the sandbars at golden hour and the glowing bay after dark—in one outing. Pick the late-night tour if the bio bay alone is your focus and you prefer to skip the sandbar stop.

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Top questions

What exactly is bioluminescence and why does the water glow in the bio bay?

Bioluminescence is light produced by living organisms—in this case, dinoflagellates in the water that emit a blue-green glow when disturbed by movement. The bio bay is one of only five in the world where this happens, and the only one where swimmers can enter the water and trigger the effect around their own bodies.

How long do I actually spend swimming in the bioluminescent water?

You swim and play in the bio bay for 30 minutes. On the sunset tour, you also swim at the sandbars before heading to the bay, so the total water time is longer, but the bio bay itself is the 30-minute window.

Do I need to bring my own snorkeling gear or towel?

Snorkeling gear is not included in this tour. Towels are also not provided, so bring your own along with a change of clothes for after you get out of the water.

Can young children or babies come on this tour?

Yes, children are welcome from age 1 onward. Floaties are provided, so younger swimmers or less confident swimmers have support in the water.

What is the difference between the sunset tour and the late-night tour?

The sunset tour includes a swim at La Parguera's sandbars before sunset, then the bio bay swim after dark. The late-night tour goes straight to the bio bay and skips the sunset stop. The late-night option runs during high-demand season only.

What language does the guide speak?

The guide speaks both English and Spanish, so you can choose which language you prefer for the safety briefing and any commentary during the tour.