Kayaking the Bio-Luminescent Bay from Fajardo, Puerto Rico

The Bio-Luminescent Bay, or Mosquito Bay (don’t be alarmed, it’s not that bad!) in Puerto Rico is considered to be the best example of a bioluminescent bay in the United States (we say “best” here tentatively, as we like to stay away from saying something is the “best” of anything as it really does depend on experience!) The bio-luminescence is caused by a micro-organism in the water, dinoflagellate Pyrodinium bahamense, which glows as a defense mechanism whenever it is disturbed. So in essence, it glows when you kayak over it, or run your fingers through the water.

Have you seen our video on exploring Puerto Rico yet?

Note that there are two Bio-Bay tours: one from Fajardo, and one from Vieques. This article refers to the bio-bay tour from Fajardo. Many of you may be looking to see if it is worth taking the tour to Vieques just for the Bio-Bay tour. We cannot answer this question; only that the one from Fajardo tends to get more crowded than the one from Vieques since it is easier to get to.

Booking a kayaking tour through the bay is among the top considerations you may make when planning your trip to Puerto Rico. We put together this guide to help you make your decision whether to book a tour to the bay or not. You’ll find that Christian and I actually had very different experiences during our trip, so we tried to record both our experiences succinctly below to help you make an informed decision.

Bio-Luminescent Bay in Puerto Rico Fajardo
Note that it’s pretty impossible to take pictures during your tour as a flash light will disturb the luminescence, so this post has very few pictures! This is us, before the tour!

Do: Book ahead

We cannot stress this enough. Even though we visited in early April, and closer to a full moon day in Puerto Rico (note the hindrance of the latter below!), booking a tour for the same day or even the day after (or week after, in some cases!) was impossible. After discussing the issue with a host of vendors, both via telephone and online, we can confirm that you really need to book your tour to the bio-luminescence bay well in advance. We would suggest at least two weeks before your desired date to take the tour.

You can sometimes get lucky and show up the day of, and due to a cancellation, get offered a place at the pier. We wouldn’t recommend this course of action!

Do: Look up the monthly moon cycle before you book your date

This is extremely important when booking the tour. The glow of the luminescence is only really evident when it is completely dark. The light of the moon can severely obscure the luminescence. Certain companies like Kayaking Puerto Rico take measures to help you see the luminescence even when it is closer to a full moon e.g. giving you a gigantic tarp to cover a group of kayaks with so that you can observe the luminescence in the dark by running your fingers through the water while under the tarp. You are also instructed to then kayak closer to the mangrove trees in the bay where it is darker to observe the luminescence by again running your fingers/oar through the water. However, as a couple who did take the tour closer to the full moon, we can say if you are singularly interested in seeing the luminescence during your tour, you need to look up the monthly moon cycle and book a date away from the full moon for your tour. While we saw some glow under the tarp and on our oars during our tour, it was nothing to write home about. Most companies are extremely upfront about this and will inform you of this before your trip – but not all will do so.

Do: Book with Kayaking Puerto Rico

After considering a host of companies in the area, we can strongly recommend Kayaking Puerto Rico if you decide to book a tour of the Bio-Luminescent Bay. They are extremely efficient and friendly in handling the details of your booking, and have a 48-hour cancellation policy just in case something comes up and you need to cancel the tour. You will require a credit card for your booking, and a 50% charge will occur if you cancel less than 48 hours before your tour. You will not be charged in case of a cancellation by the company due to weather conditions.

Their guides are all students or practitioners well versed in marine biology who are friendly, straight-forward, and can give you excellent information about the bay and its ecology. They cater to all ages and are fluent in English and Spanish. There is a no-nonsense yet extremely friendly attitude with their staff which we particularly enjoyed during our trip; unlike most guides, they didn’t overwhelm you with information, but were succinct and informative when necessary. Our favorite part is that while they are one of the cheapest kayak operators in the area (and yet provide a very safe, enjoyable service!), they give you an additional discount if you take your tour closer to the full moon, due to the low visibility of the luminescence in the bay. This really speaks for the integrity of the company. They even take pictures of you before, during, and after the tour, and share them via Dropbox with you at no additional cost. They take a group picture at the end if you stick around. If you’re planning a trip of the bay, we strongly recommend booking with Kayaking Puerto Rico!

Note that this is not a sponsored post: we genuinely appreciated our experience with Kayaking Puerto Rico and would like to recommend them to fellow travelers!

Bio-Luminescent Bay in Puerto Rico Fajardo
Checking in with Kayaking Puerto Rico. Other tour operators have a similar set up in the park.

The experience

The experience itself takes around 2.5 hours, including check-in, prep time, kayaking, and photographs afterwards. When you arrive at the pier, you are asked to check in with your specific company (most of them have tents in the park in the area), and are asked to give over any valuables to be locked up during your trip, on land. Do not bring more than a phone and car keys with you to check-in if you can help it. You cannot take your backpack on the kayak with you – it will get soaked. We recommend wearing a swimsuit and a cover up for your trip as you will get wet. Shoes are usually stored on land during your trip. After check in, you are given a briefing by your guides (overview of the ecology of the bay, have you ever kayaked before, etc.) and then the kayaking begins!

Remember: You will be kayaking as part of a large group

Unless you arrange a private tour for yourself, or get a permit and kayak yourself, you will be kayaking as part of a tour on the bay. There are one person and two-person kayaks. You are usually asked to kayak in a line through the bay, one behind another. It gets messy, but not too loud. If you’re expecting a serene, private kayaking trip through a bay, this is not it.

Don’t: Worry if you’re a first time kayaker – it’s simple enough

The person at the back of the kayak, if you’re on a two-person kayak, does most of the work. Kayaking for the first time is not too bad, as long as you’re somewhat in sync with your partner. They do call the two-person kayaks “divorce kayaks” but don’t be alarmed – you won’t be the only first time kayaker on tour, and you’ll get the hang of it soon enough!


If you are pregnant, have physical conditions, epilepsy, heart conditions etc., you will not be allowed to participate. The maximum weight of 285lbs per person and 485lbs per kayak. The minimum age requirement is 6 years. Other companies also offer electric boat rides (no kayaking required) through the bay at a higher cost, if you’d prefer that option.

Do: Look up the location of the pier beforehand

Google Maps does not always take you to the correct location and neither does a conventional GPS, so we recommend looking up the exact location beforehand, and/or calling your company and asking for directions when in Fajardo. While the company will send you their own map when you book the tour, you should keep their number handy, to call, just in case. We had to!

Do: Bring a change of clothes, a towel, and a rain jacket with you

There are showers for after your trip, so we suggest you bring a change of clothes and a towel. You will get wet during your trip, so this is highly recommended! You can leave these items in your car or with the company and change after the trip. Parking is free.

Do: Use bug spray

It’s not called the Mosquito Bay for nothing. Kayaking Puerto Rico thoughtfully provides you with bug spray before your trip but make sure you do put on bug spray before going on the tour.

Is it worth it?

And the final question: is it worth it? That’s probably why you’re reading this article, right?! We would recommend keeping your expectations low when it comes to the luminescence; it’s not always like it is in the pictures! It all depends on your experience of course; if it was a full moon day or not, whether you are looking for a night-time kayak and not only the luminescence. I (Kulani) personally would not take this tour, as I did not enjoy the night-time kayak as much as I enjoy a day-time kayaking trip (and I really like kayaking!) It was a bit too touristy for me, and this was not helped by the fact that I did not see much luminescence, as we traveled there closer to a full-moon day. Christian, however, really enjoyed the trip and would do it again. So it really depends on what you are looking for: 1) luminescence? Make sure you plan ahead 2) a night-time kayaking experience? Go for it! 3) A quiet ride through a bay? Not for you. We can both however agree that we appreciated the service offered by Kayaking Puerto Rico.

Bio Bay Fajardo Puerto Rico
Thanks to Kayaking Puerto Rico for the capture!

In summary:

Do: Book ahead, at least 2 weeks in advance of your desired tour date

Do: Note that the tour from Fajardo tends to get more crowded than the tour from Vieques.

Do: Remember you will need a credit card to make your booking

Do: Look up the monthly moon cycle before you book your date

Do: Book with Kayaking Puerto Rico

Remember: You will be kayaking as part of a large group

Don’t: Worry if you’re a first time kayaker – you’ll get the hang of it, and you won’t be the only one!

Don’t: Go on the tour if you are pregnant, or suffer from epilepsy, heart conditions, physical ailments etc.

Do: Look up the location of the pier beforehand

Do: Bring a change of clothes, a towel, and a rain jacket with you

Do: Remember parking is free, and you can store your items in a backpack in your car, or with the tour operator if necessary. Don’t take your backpack with you, it will get soaked

Don’t: Bring more than a phone and car keys with you to check-in if you can help it. Leave other items in your car if you have one

Do: Keep expectations low!

Do: Use bug spray

Explore the rest of the do’s and don’ts of Puerto Rico with us in Traveling Puerto Rico (coming soon! Subscribe to stay updated!) Watch our adventures in Puerto Rico here!

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As always, be a conscious traveler: Take nothing, and leave nothing behind. Be conscious, be welcome! Read more about conscious travel here.


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