Night boat trips cost $65 to $70, and swimming is allowed most nights. A 2015 study measured about twice as much glow in the wet season as in the dry season.
The glow is easiest to see when the moon is down during tour hours, roughly 7:30 to 10 pm. The next run of dark evenings is Oct 30 to Nov 12. Estimated from the moon's phase and typical rise times, so treat it as a guide and check the forecast for clouds.
Dark: moon down or nearly new Some moonlight Bright moon
| Operator | What you get | From | Length | Group | Min age | Cancellation | Book |
|---|---|---|---|---|---|---|---|
Island Hopping Kayak TourIncludes Snacks, Bottled water, Life vest |
$50 per person |
3 hours, 8:00 AM departure |
4+ (ages 4-10 ride in the middle of a tandem with two adults) | Check dates | |||
Bioluminescent Bay Water Bike Tour in La Parguera |
$63 per person |
Approximately 1.5 hours |
10+ | Check dates | |||
La Parguera Bioluminescent Bay Small-Group Boat Tour |
$65 per person |
1 hour |
Small group |
Check dates | |||
Hobie Pedal AdventureIncludes Hobie Mirage pedal kayak, Paddle, PFD, Dry bag, Snacks, sodas and water |
$65 per person |
3 hours |
Six tandem kayaks available |
Check dates | |||
Bio Bay TourIncludes 30-minute swim in the bay, Soft drinks, beer and water, Guide briefing on bioluminescence, Mangrove passage |
$70 per adult |
Check dates | |||||
Sunset Biobay CruiseIncludes Empanadas, Water, soda and beer, Mangrove cruise, Swim at Cayo Caracoles, About 30 minutes swimming in the bio bay |
$85 per adult |
2 to 2.5 hours |
Check dates | ||||
La Parguera 3-in-1 Private Boat Charter: Cays, Sunset & Bio BayIncludes Daytime cay stops, Sunset, Night bio bay visit |
$895 per group |
Private, 6 guests |
Check dates |
From each operator's own website, checked October 22, 2026. How we compare.
Tours leave from the La Parguera waterfront in Lajas, according to Discover Puerto Rico. The board puts it about 2 to 2.5 hours by car from San Juan and about an hour from Rincón. Paradise Scuba & Snorkeling Center checks guests in at Road 304 Km 3.2. Caribbean Chiliboats' water bike tour meets at Punta Papayo, and Kayaking Parguera's Hobie trip meets at the La Parguera Boat Ramp, while its Island Hopping tour sends directions by email.
Scientific papers call the bay Bahía Fosforescente or Bahía Bioluminiscente. Paradise Scuba's boat reaches it through the mangroves, and the guide briefs guests once in the bay. Kayaking Parguera's daytime Island Hopping route takes in the mangrove canals, the bay and the shores of the La Parguera Keys, with a swim stop at Cayo Caracoles.
Pyrodinium bahamense dominated the bay in the wet season, according to a 2015 dissertation on Bahía Fosforescente. It averaged 78,000 cells per liter in 2010 and 6,800 in 2012, with occasional blooms near 100,000. In the dry season the non-glowing Ceratium furca took over. High Pyrodinium counts followed nutrient pulses after rain, which the author links to runoff from land, and wind-driven currents moved both species around the bay from day to day.
Dry-season bioluminescence measured about half the wet-season level, the dissertation found, and its dry-season peaks came from another glowing genus, Protoperidinium. Reviewing fifty years of studies, the author found ups and downs but no long-term decline. A 2003 monthly survey, published in 2006, averaged 50,618 Pyrodinium cells per liter here, against 286,411 in Puerto Mosquito on Vieques.
A bright full moon makes the glow harder to see, Discover Puerto Rico says, so check the moon phase before booking. The dinoflagellates give off a brief flash when the water is disturbed. The board's bio bay guide calls La Parguera the only bay in Puerto Rico where motorboats are allowed, and it suggests calling ahead to confirm visibility.
Most nights you can swim in the bay, but Discover Puerto Rico says it is not guaranteed, so confirm with your operator and wear any flotation gear it requires. Paradise Scuba's night trip includes 30 minutes in the water and says every participant must know how to swim. The board also asks visitors to bring only the items their operator permits aboard, along with light clothing, a towel and water.
In June 2023 the DRNA ordered the bay closed for three nights at every full moon, under Administrative Order 2023-02, Primera Hora reported. The agency said it would use the closures for maintenance, patrols and conservation. Ernesto Weil, director of marine sciences at the University of Puerto Rico at Mayagüez, told Metro the order aims to keep motorboats out, because their fuel and oil stay on the surface. None of the operator pages checked mention the closures, so ask when booking.
Caribbean Chiliboats takes riders aged 10 and up on its water bikes. Kayaking Parguera seats one child aged 4 to 10 in the middle of a tandem with two adults. Its Hobie pedal kayaks list a per-seat limit of 275 lbs in one place and 250 lbs in another. Kayaking Parguera does not allow collecting marine life, and Discover Puerto Rico asks visitors not to touch or handle it or to use flash photography.
Paradise Scuba & Snorkeling Center charges $70 per adult, $35 for children 5 and under, and nothing for infants under 1. Its night bio bay boat runs Mondays, Wednesdays and Fridays, leaving at 8:30 pm from November to January and 9 pm from February to October, with check-in 30 minutes earlier. Water, soda and beer are included. The company says it is endorsed by the Puerto Rico Tourism Company and the DRNA.
Caribbean Chiliboats sells a 1.5-hour water bike tour from $63, which it likens to kayaking but more comfortable, and a 1-hour small-group boat tour from $65. Its 3-in-1 private charter for up to 6 guests combines the cays, sunset and the bay from $895. Kayaking Parguera lists no night tour. Its 3-hour Island Hopping paddle leaves at 8 am for $50 plus a $3 park fee. Its Hobie pedal trip costs $65 at 8 am or $99 at 11 am, plus a $3 DRNA fee.
from $50 per person
Island Hopping Kayak Tour and 1 more option
Daytime kayak trips; Island Hopping route passes the Bioluminescent Bay, mangrove canals and La Parguera Keys
from $63 per person
Bioluminescent Bay Water Bike Tour in La Parguera and 2 more options
Pedal-powered water bikes ('Chiliboats') on the night bio bay tour
from $70 per adult
Bio Bay Tour and 1 more option
Boat trip with swimming in the bio bay; all participants must know how to swim
Prices and policies come from each operator's own pages, read on October 22, 2026. Seasons, rules and local details come from the pages below.