Interpretive Eco-tours of the World's Brightest Glowing Bay!

Island Adventures - Vieques, Puerto Rico - Bioluminescent bay tours
Vieques Island, Puerto Rico

"Hidden along the Caribbean coast is one of the most spectacular Bioluminescent Bays in the world. The mysterious blue-green light is created by micro-organisms which thrive in an environment uniquely suited to their needs. A trip into the bay on a balmy night is a magical experience." - Captain Sharon Grasso

Island Adventures Biobay Tours
offers nightly excursions aboard our electrically powered double-pontoon boat through the amazing glowing waters of Puerto Mosquito in Vieques Island. Our bilingual guides explain the fragile ecology of the plants and animals of the bay, give interpretive star lectures, and then park the boat in an area of high bioluminescent concentration, giving visitors the chance to view the millions of glowing creatures.

Please check our Moonwatch Calendar for the best dates to visit the bay.

To book a biobay tour:


Why does the water glow?

This unique bay contains up to 720,000 single-celled bioluminescent dinoflagellates per gallon of water. These half-plant, half-animal organisms emit a flash of bluish light when agitated at night. The high concentration of these creatures (Pyrodimium bahamense) can create enough light to read a book from. Learn more by reading several articles on the bay.

Island Adventures is dedicated to creating awareness for this rare and endangered Bioluminescent Bay. With these first ever photos by Frank Borges LLosa at, people can now virtually experience this natural treasure which is being threatened by local development.

Conservation Regulations

The Puerto Rico Department of Environment and Natural Resources manages the Puerto Mosquito area of the Sun Bay Nature Reserve. There is a DNER regulation to help preserve the bay by prohibitting swimming in the water and for that reason our guests view the amazing glow aboard our electrically powered pontoon boat.

How to help save the Biobay:
Vieques' biobay will meet the same fate as countless destroyed ecosystems across the planet unless people speak up against unregulated development. You can help by signing the Island Adventures Guestbook and being a part of our "Friends of the Biobay" petition

T-shirts for sale

Examples + Prices

To order: Email or call 787-741-0720

Reserve your Biobay Eco Tour with Island Adventures now!
These images are strictly (c) Frank Borges LLosa / photography. To use these images in any way contact Frank at