If you haven’t seen the magic of one of the world’s bioluminescent bays in person, you’re missing out on a remarkable bucket-list experience.  There are a total of only five bioluminescent bays (bio bays) in the world, with three of the five being in Puerto Rico.⁠

Although not the brightest of the options, the location I visited was the La Parguera bio bay.  I was traveling to this area of Puerto Rico already so I researched and decided to go with a company with a small motorboat that fit about five or six people.⁠

I checked the moon calendar beforehand and scheduled the excursion accordingly.  Luckily, on the night I planned, the sky was crystal clear with a new moon and 0% illumination.  Although it’s said that the La Parguera bio bay is overcrowded and supposedly the darkest of the bays in the country, what I experienced was a breathtaking light show with only a handful of people on the only boat in the bio bay.  Take that information for what it is.⁠

Bioluminescent bays are rare ecosystems in which very high concentrations of microscopic organisms called dinoflagellates reside.  When stimulated by movement, these organisms light up and the water glows as well as everything they come in contact with.  It’s a sight to see!

And speaking of a sight to see, each and every picture you’ve ever come across of any of the five bio bays is fake.  The reality is that a bio bay is virtually impossible to photograph or record because the dinoflagellates illumination is exceptionally brief at less than one second before vanishing back into darkness.  This doesn’t mean the light show is subtle, but instead that the photographs you see online are either drastically edited, or captured using long shutter speed, regardless, neither are genuine.

I’m uncertain of the current rules, and I have heard that swimming is now prohibited, but when I went, they allowed us to swim in this glowing water.  Check with your boat crew on this before you go.  If it’s an option, I highly recommend it.

As you boat into the bay, you’ll notice a greenish-blue light trail in wake of your vessel.  You can also run your hand through the water and watch as it glistens and twinkles.  If you choose to plunge in, your skin will actually look as if it’s glowing.  Swimming and splashing around causes a burst of light and is an inexplicable experience.

Although I was totally in my glory and could have swum around the entire night, I was limited to about 30 minutes or so before being called back to the boat.  Once all were aboard, the crew passed out some fresh empanadas and ice-cold beers for everyone to enjoy on our way back to the dock.  The entire excursion lasted about two hours, and we had plenty of time left in the night to enjoy a nice dinner and some drinks in town afterward.

Why Should You Add Visiting a Bio Bay to Your Bucket List?

There is no other way to experience it.  Period.  Pictures can’t capture it, and no description could possibly paint the picture as vivid as the real thing.

Should You Swim in a Bio Bay?

Absolutely, YES!  However, there are a few ethical and environmental components to consider, and keep in mind, some people may be disapproving of your decision regardless of how cautious and aware you are.

One of the main concerns of swimming in the bio bays is the large number of visitors and the chemicals on their bodies such as bug spray, and suntan lotion which could be detrimental to the survival of the dinoflagellates. However, I really wanted to swim in the bay and get the full experience, so I inquired and received a little science lesson from my boat captain.  I obviously didn’t want to be destructive to one of the natural wonders of the world, so I made sure to find out just exactly what damage, if any, swimming in the water causes.

Bioluminescent dinoflagellates are present throughout the ocean, however, they are just not usually found in such high concentrations.  Therefore, the great variation in brightness isn’t caused so much by over-tourism, but instead by complex ecological circumstances which cause greater or lesser dinoflagellate concentration in the bay at any given time.

Therefore, swimming in the bio bay is not a destructive decision.  We’ve done it for decades without any ill effect on the bays.  Tour companies have just been limiting or not allowing swimming in recent years to limit the chemical pollution from our bodies.  So please, just remember, if allowed, and you choose to swim in any of the bays, be certain your body is free of any and all chemicals!

One Last Quick Helpful Tip

When booking, request the latest possible time or ask to go when the company recommends the bay is likely to be empty. Swimming in a bio bay is magical. Swimming in a bio bay with no one around aside from your boat captain and 5 friends is something close to nirvana. We were blessed to be completely alone in the bay, and it was an experience that I will cherish forever.