MOSQUITO BAY on the island of Vieques, just off the shore of Puerto Rico, is home to the world’s brightest bioluminescent display. In the waters of the small bay live tiny organisms called Dinoflagellates, a type of plankton that glows blue when disturbed. Mosquito Bay isn’t the only place in the world where this phenomenon happens, but it’s the brightest — it was officially honored in 2008 by the Guinness Book of World Records. The intensity is due to the high concentration of plankton in the small bay’s shallow waters, and the way the organisms are “trapped” because of the small mouth of the bay.

How to visit Mosquito Bay

There are a couple of options to get to the island of Vieques from the mainland. From San Juan you can fly with either Vieques Air Link or Cape Air, and from there it’s a short ride to Mosquito Bay. If you’re looking to save money you can take a ferry from the port town of Fajardo, but you will have had to make your own way from San Juan, about 37 miles away. There are other options as well depending where in Puerto Rico you are. For more details, this is a great site for information.

There’s an abundance of guided options for exploring the bay as well. According to vlogger Mike Corey, who produced the amazing video of the bioluminescence below, “Black Beard Sports has the best operation” and are also one of the only dive operators on Vieques.

Other considerations when visiting Mosquito Bay

Mike shared some other important considerations when planning your trip to Mosquito Bay:

  • Bring bug spray, it’s called Mosquito Bay for a reason.
  • You can’t swim in the bay, or use boats with propellers. Sunscreen, gasoline, etc. harm the plankton. Ever since this rule was put in in place a few years ago, the bay’s bioluminescence has become the brightest in the world. You will kayak out to see the bioluminescence.
  • The brightness of the glow is affected by many things – after all, it’s created from a living organism. Rain dilutes the bay, drops the salinity, and decreases the glow. For best times to visit, refer to this article.
  • Even on Venue’s, brightest days, it’s not that useful bringing a camera. GoPros and 95% of DSLRs do not have a sensor big enough to capture the light. The image will just be black. Some particular cameras (e.g. the Sony a7s), created especially for low light can just barely capture this phenomenon.
  • It is common to see sharks swimming through the lagoon. All you will see is a shimmering blue outline like a shark shaped meteor.

What you will see at Mosquito Bay