I sat silently in my kayak, one hand swirling the water outside the boat. With each gentle swish, a miniature constellation of underwater “stars” twinkled around my fingers. In the kayak beside me, a woman spun her paddle in the water and gasped at the tiny explosion of light. Ahead of me, the comet-like streak of green in the water indicated a fish swimming near the surface.
I’d come to Isla de Vieques, off Puerto Rico’s main island, to kayak its world-famous bioluminescent bay. The experience was everything I’d hoped for — a stroke of luck, given how poorly I’d arranged my trip. Getting the most out of a bio bay tour requires a lot of advance planning, and, in the case of Vieques, more cash than you might expect.
Here’s what I wish I knew before making the trip.
1. Bioluminescence Is Surprisingly Common
Much like fireflies do on land, single-celled, water surface–dwelling organisms called dinoflagellates, a type of plankton, can emit light underwater. They aren’t the only marine organisms that glow. Some 1,500 species of fish are known to luminesce, as well as certain types of squid, jellyfish, worms, and crustaceans. Many use bioluminescence as lures for food or mates, or to confuse predators.
Although dinoflagellates are microscopic, they often form large colonies. The human eye doesn’t detect the bioluminescence when a water body is still. But when disturbed, such as by wind that ripples the surface or the slicing of a boat hull through the water, our eyes translate the light wavelengths into glow-in-the-dark sparkles and zigzags of green or blue-green.
Choose a reputable tour operator to make the most of your bioluminescent bay kayaking experience.
Photo credit: Discover Puerto Rico2. Puerto Rico Has Three Bioluminescent Bays
The planet currently has five ecosystems where dinoflagellate concentrations are high enough to consistently cause this bioluminescent phenomenon. Puerto Rico claims three of them.
In Fajardo, along the east coast of the main island, Laguna Grande is the most trafficked of the trio. It’s not as bright as the others, but at only an hour by car from San Juan, it’s the easiest to get to. This also makes it the most touristy of the bunch.
A few of the better-known Laguna Grande tour operators include:
In Lajas, on the opposite corner of the main island, La Parguera is the least visited of the three bays. At about 2.5 hours from San Juan, it’s a much longer drive than Laguna Grande, but a worthwhile stop if you’re visiting the western side of Puerto Rico.
Some tours allow swimming in La Parguera. Because chemicals in bug repellents, sunscreens, and body lotions can kill the phytoplankton, you’ll need to shower before joining a tour that includes swimming or diving through the bio bay.
Try one of these La Parguera tour operators:
The granddaddy of all bioluminescent bays, and the brightest in the world, is Mosquito Bay in Vieques. Although Hurricane Maria devastated the island in 2017, Mosquito Bay’s dinoflagellate population has, miraculously, doubled since then. On a dark night, you’re almost guaranteed to see something spectacular.
Tour operators on Vieques include:
You can rent a car and drive to Laguna Grande or La Parguera. Mosquito Bay isn’t connected to the main island, so you’ll need to take a ferry (about $40 per person) or small plane (about $120 per person) from Ceiba, or fly directly from San Juan (about $130 per person), to get there. Depending on the time of year, ferry and flight service may or may not be available after 7 p.m. Residents are given preference on the ferry, which means you could get bumped from an especially full voyage.
In addition, many bio bay kayaking tour operators require an address where you’ll be staying on the island in order to complete booking. Since cars aren’t allowed on the ferry to Vieques, you must rent a car or line up a taxi ride once on the island.
The short story: It’s best to plan an overnight stay on the island.
Between our flights, taxi, accommodations in the least expensive Airbnb we could find, and the tour itself, my husband and I spent about $450 on this portion of our trip.
We chose Abe’s Snorkeling for our excursion. The experience was very good overall, although the tour operator, like an airline, oversold their 7 p.m. tour. About a dozen of us were bumped, with no notice, to the 9 p.m. slot. For our trouble, our guide offered each pairing of people a refund on one ticket.
Although you won’t be alone on the water, you might feel like you have the bay all to yourself.
Photo credit: Discover Puerto Rico4. Almost Anyone Can Do It
Bio bay kayaking is appropriate for most levels of ability. The water is usually calm, and paddling is done at a laid-back pace, mostly in two-person boats. Because you’re kayaking in the dark, it’s important to follow your guide’s instructions and stick close to your tour group. This could be tricky for travelers with vision or hearing impairments. If you’ve got grandkids in tow, ask about age restrictions.
5. Know Your Moon Cycles, And Book In Advance
You might be able to book a tour on the fly, but I wouldn’t risk it. Most fill up several months in advance, especially during the high season.
Although Puerto Rico’s bays luminesce year round, you’ll have the best experience on a dark night. Kayaking during a new moon is preferable because the glow percentage is usually higher. Using a moon phases calendar will help you chart out the best time to go.
Most operators don’t even run tours 3 days before or after a full moon. We didn’t realize this when we booked our Puerto Rican vacation. Fortunately, the final night was just beyond the full-moon window.
The day before or the morning of your excursion, call your tour operator to check on the bay’s brightness; it should be a minimum of 30 percent. In addition to the moon, tides and water temperature affect how much color you see.
Some tour companies offer clear-bottomed boats, which allow for a unique look at the bioluminescence directly underneath you. This isn’t the default option, so be sure to ask if it’s important to you.
7. Dress To Get Wet
Wear comfortable clothing, such as shorts and a T-shirt, preferably made of tech or quick-drying fabrics; some splashing is normal during any kayaking outing. Pants and shorts with zipper pockets are useful for storing a credit card, in case you want to stop at a restaurant or bar on the way back to your hotel or Airbnb (no need to take a full wallet or cash). Sturdy walking sandals, knit sneakers, or aqua shoes are all good choices for footwear.
Don’t count on being able to stash extra clothing or shoes with the tour operator; take only what you need.
8. Skip The Sunscreens And Skin Lotions
Wash your hands and feet before the trip, and don’t apply any moisturizer, serums, or lotions. You’ll be allowed to dip toes and fingers in the water, but chemicals from common skin products can kill the dinoflagellates.
9. It’s Okay To Take Your Phone
Most bio bay operators will tell you to leave your cell phone behind, ostensibly because its camera won’t be able to capture the glow. This may be true, or it may be an effort to reduce the sharing of images, which might, in turn, lead to a reduction in tour purchases. I regretted listening to this advice. I think I could have used my cell phone camera in manual mode and gotten sufficiently long exposures to photograph some of the luminescence.
Bottom line: There’s no harm in taking your phone, as long as you seal it in a floating dry bag, and wear it on a lanyard around your neck. Just be aware that if you accidentally overturn your kayak, you might have trouble retrieving the phone in the dark. And don’t spend all your time taking pictures. The best part of the experience is staying in the moment and enjoying the display.
10. Be Prepared For A Wild Ride
The drive out to the bio bay is a bit like riding a roller coaster without a seat belt. Our bus driver clearly had been making this drive for years, and he knew every pothole and curve in the road — and took most of them at a robust clip. In the dark. I had to pry my fingers out of the seat upholstery after he swerved through small herds of the island’s free-roaming horses. Fortunately, he didn’t hit any.
Pro Tip: About those Viequense horses: They’re not wild, even if tourism brochures and resorts market them as such. All are owned by residents and are set free to browse the island’s grasses when not being used as transportation. Sadly, these beautiful animals are frequently killed in road accidents. If you rent a car, drive slowly and cautiously.
The glow of the phytoplankton is usually enhanced in photos, as you see here. Still, the experience of kayaking a biobay on a dark, clear night is nothing short of magical.
Photo credit: Discover Puerto Rico11. Keep Your Expectations In Check
Nature is fickle, and an evening of 100 percent glow might be followed by one of less than 30 percent. To make matters worse, all promotional images of bio bay tours are Photoshopped. While it is a breathtaking sight, you will not be engulfed in a happy blue halo, nor will the water light up on its own. What you’ll see is more akin to an underwater shower of glitter every time you or your tour mates dip an oar or hand into the bay.
That’s a big yes. Although I can’t speak for Laguna Grande or La Parguera, kayaking Mosquito Bay was as close to magical as an outdoor experience can get. The bay is wide open and hushed, and even with other groups of kayakers out on the water, it felt like we were the only ones. Paddling was relaxed over the hour and a half we spent out on the water.
Because I’d read up in advance and scaled my expectations, I wasn’t disappointed. The bioluminescent glow was actually more pronounced than I figured it would be, with miniature fireworks going off each time a boat pushed through the water. It wasn’t the neon blue radiance shown on tour websites, but it still felt otherworldly, like holding a galaxy of tiny stars in my palms.
Related Reading: