Laguna Grande mangroves
Mangroves line Laguna Grande's shore and the channel from Las Croabas. You paddle through that channel to reach the lagoon, where moving water can flash blue.
Things to do in Puerto Rico › Places › The bioluminescent bays
The bioluminescent bays
three bays · darker nights show moreUpdated October 8, 2026 ferry fares from Puerto Rico Ferry; viewing advice from Discover Puerto Rico
Laguna Grande is in Fajardo; Mosquito Bay on Vieques is the brightest bay on record. La Parguera is in Lajas on the southwest coast. You paddle by kayak or join a boat tour. You can't swim at the first two; some La Parguera boat tours offer a swim. Dark nights around the new moon show the glow best. Tours start from $60 per adult on Vieques; your ferry or flight costs extra.
The three bays
The three bays: access and swimming
| Laguna Grande | in Fajardo's Las Cabezas de San Juan reserve. You kayak through a mangrove channel from Las Croabas on a 2-hour trip. |
| Mosquito Bay | the brightest bay on record, on Vieques's south coast near Esperanza. The clear kayak trip includes local transfers and takes 90 minutes. |
| La Parguera | in Lajas on the southwest coast. Boats leave from the village area; the listed boat and water bike trips start at Punta Papayo. |
| Swimming | no swimming at Laguna Grande or Mosquito Bay. Some La Parguera boat tours offer it; the water bike tour doesn't. Your swim depends on the tour you book. |
| Best nights | the darkest nights around the new moon. Some tours skip full-moon nights; you can't assume each bay runs the same schedule. |
| Tours | twelve tours from $60 per adult in the bio bay list. Prices cover the booked activity; your ride to the start may cost extra. |
Which bay
- Laguna Grande Laguna Grande suits a night out from San Juan without leaving the main island. Your ride to Las Croabas isn't included in either listed kayak trip.
- Mosquito Bay Mosquito Bay is the brightest bay on record and suits an overnight stay on Vieques. You'll need a ferry or flight to reach the island.
- La Parguera La Parguera suits a stay in the west and a visit without paddling. If you want a swim, choose a boat trip that offers it.
Map
Where the bays are
Laguna Grande: 18.3767° N, 65.6237° W Directions in Google Maps Apple Maps OpenStreetMap
How to get there
- Laguna Grande Las Croabas is 65.2 km by road from Muelle 1 in Old San Juan, or 40.5 miles. You meet at the waterfront for your kayak tour. Arrive 30 minutes early for the trip from $67 per person.
- Mosquito Bay The Ceiba ferry terminal is 73.2 km, or 45.5 miles, by road from Muelle 1 in Old San Juan. The Vieques crossing takes 1 hour and costs $2.00 each way for adults 13 to 59. Vieques Air Link also flies from San Juan's Isla Grande airport.
- La Parguera La Parguera is 174.7 km, or 108.6 miles, by road from Muelle 1 in Old San Juan. The listed boat tour starts at Playa Punta Papayo. Follow Road 324 to kilometer 1.9, then continue to the shore.
- With a tour from San Juan The El Yunque and Laguna Grande combination takes 12 hours from $183.98 per person. Pickup uses set meeting points; in Old San Juan it's Pier 6 by the Seahorse Statue. Dinner isn't included.
The bays
What you see at the bays
Laguna Grande mangroves
Mosquito Bay at night
A tour boat sits on Mosquito Bay after dark. Tiny plankton flash when your paddle stirs the water. The listed 90-minute trip uses clear kayaks so you can see beneath you.
La Parguera waterfront
A stilt house and boat mark La Parguera's waterfront. You can reach the glow by water bike or a boat that doesn't require paddling.
Vieques by day
Vieques has beaches for the hours before your evening bay tour. The clear kayak trip meets across from Sun Bay's entrance.
With a guide
The bioluminescent bays: six ways onto the water
Six tours into the bays, lowest price first. Each row pairs a starting price with the exact trip and the travel you still need to arrange.
| Clear kayak on Mosquito Bay | $60 per adult | Vieques island Biobay Kayaking Tour 491 reviews, 4.8 · 90 minutes; ferry or flight extra. Meet across from Sun Bay's entrance 25 minutes before your tour time. · dates and prices ↗ |
| Kayak at Laguna Grande | $67 per person | Puerto Rico Bio Bay Kayak Adventure Tour 1,821 reviews, 4.6 · 2 hours; your ride to Las Croabas isn't included. Minimum age 6; maximum weight 245 lb per person. · dates and prices ↗ |
| Water bike at La Parguera | $79 per person | Bioluminescent Bay Water Bike Tour in La Parguera 99 reviews, 4.8 · 90 minutes; your ride to Punta Papayo is extra. No swimming on this trip; maximum weight 240 lb per person. · dates and prices ↗ |
| Boat at La Parguera | $80 per adult | Bioluminescent Bay Boat Tour in La Parguera 62 reviews, 4.7 · 1 hour; reach Playa Punta Papayo yourself. This boat trip offers an optional swim. · dates and prices ↗ |
| Tandem kayak at Laguna Grande | $89 per person | Bio Bay Kayak Tour in Fajardo 2,177 reviews, 4.7 · 2 hours; no pickup from San Juan. Maximum weight 240 lb per person and 425 lb per tandem kayak. · dates and prices ↗ |
| Forest and bay with pickup | $183.98 per person | Two-in-One Day Trip: El Yunque and Bio Bay Tour with Transport 1,449 reviews, 4.9 · 12 hours; pickup at set locations. Dinner is extra; ages 8 to 70 and 240 lb per person maximum. · dates and prices ↗ |
The catch: The Vieques tour won't refund a missed departure. You must meet 25 minutes before your tour time. Free cancellation ends 24 hours before departure.
Before you go
- The new-moon week gives you less moonlight. Book ahead and keep a spare night for weather. Swimming at La Parguera depends on the tour you book.
Tours
Tour lists for the bioluminescent bays
Bioluminescent bay tours
12 tours · from $60
The bio bay list compares stand-alone trips and trips with transport. Choose your bay first, then compare what each price includes.
Vieques tours 6 tours · from $60Vieques tours pair island time with the evening glow. Your choices include clear kayaks and beach combinations from San Juan.
El Yunque rainforest tours 14 tours · from $25El Yunque tours include forest days paired with Laguna Grande at night. The combination with pickup takes 12 hours, so you'll need the whole day.
Know before you go
Know before you go
Moonlight
The darker sky around a new moon makes the glow easier for you to see. Some tours skip full-moon nights; Fajardo trips can use a tarp to block light.
Swimming rules
Laguna Grande and Mosquito Bay don't allow swimming. The listed La Parguera boat trip offers it; the water bike trip keeps you out. Read the swim terms for the exact option you choose.
Clothes and shoes
Clothes and shoes can get wet when you kayak. Bring water shoes for Fajardo and a towel. Dry clothes will make your ride back more comfortable.
The changing glow
The glow can fade even on a dark night. Mosquito Bay has dimmed after a hurricane and a dry spell. Your ticket doesn't guarantee brightness, and photos rarely capture the light you see.
Vieques ferry timing
Allow 1 hour for the crossing and arrive 1 hour before sailing. Boarding closes 10 minutes before departure. Children 4 to 12 and adults 60 to 74 pay $1.00 per person each way. An overnight stay avoids tying your bay tour to the last return ferry.
Hurricane season
The Atlantic hurricane season runs from June 1 to November 30. Rain alone doesn't cancel the La Parguera water bike tour; its guide decides at the meeting point. Keep a spare night if your plans allow it.
Good to know
People also ask
- Which bioluminescent bay in Puerto Rico is the best?
Mosquito Bay on Vieques is the brightest bay on record. Laguna Grande is the nearest of the three to Old San Juan. Choose Mosquito Bay if you can stay on Vieques; choose Laguna Grande for a night from San Juan.
- Can you swim in the bioluminescent bay?
You can't swim at Laguna Grande or Mosquito Bay. Some La Parguera boat tours offer a swim, including the trip from $80 per adult. The water bike trip excludes it, so read your option before booking.
- What is the best time to see the bio bay?
Dark nights around the new moon give you the clearest view. The bays can glow throughout the year. Book ahead for that week, with a spare night if weather changes your plans.
- How do you get to the bioluminescent bay from San Juan?
Laguna Grande is reached by road via Las Croabas, 65.2 km from Muelle 1 in Old San Juan. For Mosquito Bay you take the ferry from Ceiba or fly to Vieques. La Parguera is 174.7 km by road from Muelle 1. The forest and Laguna Grande combination includes pickup at set San Juan stops.
- How much does a bio bay tour cost?
Clear kayaks on Vieques start from $60 per adult aged 12 and up. La Parguera's boat tour starts from $80 per adult. Fajardo kayaks start from $67 per person; La Parguera water bikes start from $79 per person. The forest and bay combination is from $183.98 per person with pickup.
- Is the bio bay worth it on a full moon?
It can be worth it if your dates are fixed. The glow is harder to see. Some tours skip full-moon nights; the Fajardo trip from $67 per person can use a tarp. Ask how your chosen departure handles bright moonlight.