Laguna Grande

The basics

Visitors can set the water aglow and create a trail of light with every stroke of their paddles during guided nighttime bio bay kayaking tours. Laguna Grande tours are usually offered around the cycles of the moon, timed to the darkest nights. Some tours also combine kayaking with an afternoon nature walk to La Mina Falls in the nearby El Yunque National Park.

There are only a handful of places in the world where bioluminescent plankton is consistently found, three of which are in Puerto Rico. In addition to the Laguna Grande bioluminescent bay, this natural phenomenon exists in Bioluminescent Bay (Mosquito Bay) on Vieques Island and the bay at La Parguera. Laguna Grande in Fajardo is surrounded by a red mangrove forest, native to the surrounding El Yunque rainforest and a source of vitamin B12 to the marine plankton.

Things to know before you go

• Kayak tours typically navigate through a tunnel of mangrove trees before reaching the glowing waters.

• Swimming in this bio bay in Puerto Rico is not allowed; you can swim and snorkel in the bay at La Parguera.

• Guides will sometimes bring a cover so that the tour group can observe the bioluminescence in complete darkness without starlight.

• You do not need Laguna Grande tickets to access the bay.

How to get there

Laguna Grande is located in the Las Cabezas de San Juan Nature Reserve, just off the shores of Fajardo, Puerto Rico, and about 40 miles (65 kilometers) or an hour’s drive east of Old San Juan. Tours typically depart from San Juan or Luquillo, which is 9 miles (15 kilometers) away.

When to get there

Kayaking trips frequently set out in the early evening around sunset, launching from Las Cabezas with a tour guide or instructor. The best time to experience the bioluminescent bay is when the sky is especially dark due to little or no moonlight, so try to book your tour around a new moon and avoid days surrounding a full moon.

El Yunque Rainforest

Sometimes coupled with a guided tour of the Fajardo bio bay, a visit to El Yunque National Park is a must-do for nature lovers visiting Puerto Rico. It is the only tropical rainforest in the United States Forest Service and features well-defined walking trails, lush landscapes, and plenty of wildlife such as the Puerto Rican parrot and the Coqui frog.

Can you swim in Laguna Grande?

No, unfortunately, you can’t swim in Laguna Grande during your visit or tour. Swimming is prohibited to keep the bay at its healthiest. The only bioluminescent bay in Puerto Rico that you can swim in is La Parguera, which is a 2.5-hour car drive from Laguna Grande.

Why does Laguna Grande glow?

The bioluminescence bay of Laguna Grande glows with a blueish coloring because of the dinoflagellates in the water. A dinoflagellate is a microscopic organism that uses glowing as a defense when they notice any movement in the water. These short bursts of blue light have drawn tourists to the bays for years.

Can you go to bio bay without a tour?

Yes, you can go to Laguna Grande bio bay without a tour, and it’s legal to go on the water by yourself without a guide. If it's your first time at the bay, you may want to first plan a daytime visit to familiarize yourself with the surroundings.

What time of night does the bioluminescence occur?

The best time of night to see the effects of the dinoflagellate’s bioluminescence on Laguna Grande is at least two hours after the sun has set when the sky is dark. One of the best times is also during the new moon phase because there won’t be moonlight reflecting onto the water.

Can you visit Laguna Grande on your own?

No, you cannot visit Laguna Grande on your own. Take a kayaking or boat tour with a licensed, permitted tour operator to easily navigate the mangroves and get the best experience of the sparkling, bioluminescent waters after dark. Tours typically include kayaks, gear, and safety equipment.

Is Laguna Grande bioluminescent bay worth it?

Yes, Laguna Grande bioluminescent bay is worth a visit. It's one of only a few places where you can easily and conveniently see bioluminescent microorganisms illuminate the waters. Many travelers consider it one of the highlights of a trip to Puerto Rico.

How can I see Laguna Grande?

To see Laguna Grande, you need to take a guided tour. Kayaking tours are popular and generally include kayaking gear, safety equipment, and a professional guide who helps you navigate the mangroves that lead to the lagoon.

Can you see the Laguna Grande bioluminescent bay without kayaking?

Yes, you can see the Laguna Grande bioluminescent bay without kayaking, but you will need to be on the water as it’s not accessible by land. A few tour operators run tours on small boats out to the lagoon, ideal if you don’t like kayaking.

What month can you see bioluminescence at Laguna Grande?

You can see bioluminescence at Laguna Grande all year, but it's best to visit in the dry season, which runs from December–April when there’s less chance of rainfall. If possible, plan your visit to coincide with the new moon, when the sky is darkest and bioluminescence is most brilliant.

Can you go take photos at Laguna Grande?

Yes, you can take photos at Laguna Grande, but it's difficult to get still photographic images to match the brilliance of the live bioluminescence. Digital SLR cameras will likely work better than camera phones. Pack a dry bag if you don’t have a waterproof device.

Ways to explore

Visitors can set Laguna Grande’s water aglow and create a trail of light with every stroke of their paddles during guided nighttime bio bay kayaking tours. Laguna Grande tours are usually offered around the cycles of the moon, timed to the darkest nights. Some tours also combine kayaking with an afternoon nature walk to La Mina Falls in the nearby El Yunque National Park. Kayak tours typically navigate along the access channel through a tunnel of mangrove trees before reaching the glowing waters. Guides will sometimes bring a tarp so that the tour group can observe the bioluminescence in complete darkness without starlight.

Accessibility

Some tours to Laguna Grande are accessible to wheelchair users.

Age limits

None, though tours generally require that participants know how to swim

What to pack

Bug repellent, water bottle, waterproof pouch for phone and wallet, camera for night photos

What to wear

Water shoes, shorts or a swimsuit (to wade into the water when boarding your kayak)

Not allowed

Swimming in the lagoon, leaving trash or other waste in the reserve

Amenities

Most tours include kayaking gear, life vests, and tarps to block light.

Address

Laguna Grande is located in the Las Cabezas de San Juan Nature Reserve, just off the shores of Fajardo, Puerto Rico, and about 40 miles (65 kilometers) east of Old San Juan. Tours typically depart from San Juan or Luquillo, which is 9 miles (15 kilometers) away.

Driving

If you’re driving to Laguna Grande from San Juan, take Highway 3E about an hour east towards Fajardo. Park at Kayak Village—where the boat tour operator offices are clustered—in Las Croabas at the mouth of the channel that leads to the lagoon. There is free parking at the entrance to the nature reserve.

Public transportation

Public transportation is not available to Laguna Grande, but many boat and kayak tours include transfers from San Juan.

Best times to visit

By far, the best time to visit Laguna Grande is after nightfall when the bioluminescent effect is visible. Choose a night with cloud coverage or a new moon for the darkest viewing conditions.

Best days to visit

This popular attraction can get crowded with kayak and boat tours on the weekends and holidays. Choose an evening tour during the week to avoid “boat jams” along the access canal.

Best months to visit

Visit from December to mid-April for the warmest temperatures and least rainfall, ideal for spotting Laguna Grande’s bioluminescence.