Identification key
Which bay is yours?
All three glow from the same phenomenon, but they are not interchangeable. Read the key the way a naturalist would: start at couplet 1, pick the line that fits, and follow it to a bay or to the next couplet.
For the full picture
The three bays, side by side
| Mosquito BayVieques | Laguna GrandeFajardo | La PargueraLajas | |
|---|---|---|---|
| Brightness | Brightest of the three, Guinness World Record 2006 | Bright, kayak tours through a mangrove channel | Bright, unique for allowing swimming |
| Access mode | Kayak or electric boat | Kayak, or electric boat with one operator | Motorboat or glass-bottom boat |
| Swimming allowed | No | No | Yes, the only one of the three |
| Distance from San Juan | Requires a ferry or flight to Vieques, plan an overnight stay | About 45 minutes by car, the closest | About 2.5 hours by car |
| Starting price | $65 to $85 per person | $59 to $70 per person | $22 to $70 per person |
| Best for | The brightest possible glow, worth the travel | A day trip from San Juan with no overnight needed | Swimming in the glow itself |
Bay by bay
Each bay: the trip, the rules, and who runs tours
Prices are each operator's lowest published per-person rate, read from the 18 operator records on this site. Each name links to that operator's full entry.
Mosquito Bay, Vieques
The brightest of the three, with a Guinness World Records entry from 2006. It is on the island of Vieques, so the trip starts with a ferry from Ceiba or a short flight, and most visitors stay one night because the tours finish after the last ferry back. You go by kayak, clear-bottom kayak, or electric boat. Swimming is not allowed, and you cannot enter on your own: only companies holding a permit from the Department of Natural and Environmental Resources (DRNA) may take visitors onto the water.
DRNA closes Mosquito Bay to all tour companies on the night before, the night of, and the night after every full moon. There is no tour to book on those three nights.
| Operator | How you go | Duration | From |
|---|---|---|---|
| Mosquito Bio Bay Tours | clear-bottom kayak | 90 minutes | $65 |
| Abe's Snorkeling & Biobay Tours | kayak | 2 hours | $70 |
| Black Beard Sports | clear-bottom kayak | 2.5 hours total, about 1 hour of that in the bay | $70 |
| Isla Nena Biobay Boat Tours | electric boat | 40 minutes | $85 |
Laguna Grande, Fajardo
The closest bay to San Juan, about 45 minutes by car, and the only one of the three that fits into a single evening with no overnight stay. Most tours are by kayak: you paddle through a narrow mangrove channel before the lagoon opens up. One operator runs an electric boat for people who would rather not paddle. Swimming is not allowed. Fajardo operators run tours every night of the month, full moon included, though the glow is much weaker then.
If someone in your group cannot paddle, there are two options here: the electric boat, or the wheelchair-adaptive kayak that one of the kayak operators offers. Ask either about your specifics before booking.
| Operator | How you go | Duration | From |
|---|---|---|---|
| Puerto Rico Access Tours | kayak, including a wheelchair-adaptive kayak option | 90 minutes | $59 |
| Pure Adventure PR | kayak | 2 hours, including a 15-minute lesson and a 90-minute paddle | $59 |
| Eco Adventures | kayak | 90 minutes to 2 hours | $63 |
| Puerto Rico Bio Bay Tours | kayak | 3 hours | $68 |
| BioIsland | electric boat | 1 hour 15 minutes | $69 |
| Kayaking Puerto Rico | kayak | 2 hours, including a 15-minute briefing | $70 |
La Parguera, Lajas
The only one of the three where you can get in the water. It is on the southwest coast, about 2.5 hours from San Juan by car, and no operator listed here offers pickup from the capital, so you need a rental car or a driver. Most of the tours listed here go out by motorboat with a swim stop. One operator runs a glass-bottom catamaran, and two offer kayaks.
Ask your operator about full-moon nights before you book. DRNA issued an order in June 2023 closing this bay for three days of full moon in each lunar cycle, and we have not confirmed first-hand whether it is still enforced.
| Operator | How you go | Duration | From |
|---|---|---|---|
| Fondo de Cristal | glass-bottom boat (catamaran) | 1 hour | $22 |
| Torres Boat Rental | motorboat and swimming | 1 hour | $40 |
| Parguera Eco Tours | swimming (boat-based swim tour) | about 1 hour, including 30 minutes in the water | $45 |
| Aleli Tours | motorboat (19-ft skiff or 22-ft power catamaran) | varies by boat | $50 |
| Kayaking Parguera | kayak | 1.5 hours | $59.99 |
| Parguera Water Sports | kayak and swimming | not published | $65 |
| Hook'd on Adventure | motorboat, swim and snorkel | 1 to 2 hours, depending on the tour | $70 |
| Paradise Scuba & Snorkeling Center | boat and swimming | 2 hours | $70 |
When to go
The next new moons
The moon decides the night at all three bays. The darkest nights are the new moon and the three days on either side of it. These are the next four windows.
- New moon
- Best nights: November 6 to November 12
- New moon
- Best nights: December 6 to December 12
- New moon
- Best nights: January 4 to January 10
- New moon
- Best nights: February 3 to February 9
Every new and full moon for the next 18 months is on the moon calendar, where you can also check your own travel dates.
The other question
Kayak, boat, or clear bottom
The bay decides most of the trip, but the craft decides what the two hours feel like. Counts below are from the eighteen operators listed on this site.
- Glass bottom boatLa Parguera
- One operator, and the only glass-hulled vessel on any of the three bays: Fondo de Cristal runs a two-level catamaran with glass viewing panels in the lower deck. One hour, $22, the cheapest tour in this register. Mosquito Bay and Laguna Grande have none, and at those two the nearest equivalent is a clear-bottom kayak, below.
- Clear-bottom kayakMosquito Bay
- A transparent hull, so the glow is under you as well as around your paddle. Two of the eighteen operators run these, both on Vieques. Fajardo operators use standard sit-upon kayaks.
- Standard kayakAll three bays
- The most common option by a wide margin, and what five of the six Laguna Grande operators listed here run. Seven operators, and one of them runs a wheelchair-adaptive kayak. One, at La Parguera, turns away paddlers with no previous kayaking experience. How hard is the kayak tour?
- Electric boatMosquito Bay and Laguna Grande
- Two operators, one on each of those bays. No paddling, which matters if the group includes someone who cannot kayak for two hours.
- MotorboatLa Parguera
- Four operators, all on La Parguera and all running swim tours from the boat. Gas motors are restricted on the other two bays.
Every operator's craft is listed on its own card in the operator directory.
Where to stay near the bays
Still deciding? San Juan works as a base for all three: Laguna Grande is about 45 minutes out, and both the Vieques ferry and the drive southwest start from here. This map shows places to stay in San Juan.
Questions people ask about the three bays
How many bioluminescent bays are there in Puerto Rico?
Three: Mosquito Bay on the island of Vieques, Laguna Grande in Fajardo on the east coast, and La Parguera in Lajas on the southwest coast.
Which bioluminescent bay in Puerto Rico is the brightest?
Mosquito Bay in Vieques. Guinness World Records recognized it in 2006 as the brightest bioluminescent bay in the world. On any given night the moon matters more than the bay, though: a new-moon night at Laguna Grande or La Parguera will show you more than a bright-moon night at Mosquito Bay.
Can you swim in the bioluminescent bays in Puerto Rico?
Only at La Parguera. Swimming is banned at Mosquito Bay and Laguna Grande to protect the organisms that produce the glow, not because the water is unsafe for people.
Which bioluminescent bay is closest to San Juan?
Laguna Grande in Fajardo, about 45 minutes by car. It is the only one of the three you can visit in one evening and be back in San Juan the same night. La Parguera is about 2.5 hours away by car, and Mosquito Bay needs a ferry or flight to Vieques.
Can you visit a bioluminescent bay in Puerto Rico without a tour?
Not at Mosquito Bay, where only DRNA-permitted companies may take visitors onto the water. Laguna Grande and La Parguera have no equivalent published closure, but every practical route to the water at all three bays is a guided one.
How much does a bioluminescent bay tour in Puerto Rico cost?
Among the 18 operators listed on this site, the lowest published per-person rate runs from $22 to $85. By bay: Mosquito Bay $65 to $85, Laguna Grande $59 to $70, La Parguera $22 to $70. Taxes, park fees, and combination tours add to those starting prices.
When is the best time to visit a bioluminescent bay in Puerto Rico?
Within three days of a new moon, in any month. The bays glow year-round, and a full moon can wash the glow out almost completely at any of the three.
Whichever bay you land on, check the moon calendar before booking. The bay decides the trip, the moon decides the night, and what the flights cost by month decides the month.