Vieques' Bioluminescent Bay

What makes it light up?

As the sun sets billions of Dinoflagellates put on an interactive light show in Vieques’ famed Bioluminescent Bay. Dinoflagellates are tiny one-celled organisms that glow brightly when moved. A natural defense mechanism, their nightime glow attracts fish that eat smaller organisms preventing them from feeding on the Dinoflagellates.

Why is the light blue?

Blue and green light travel farther than other wavelengths in water. Most marine animals are adapted to see these colors of light.

Is it the same year round?

The dinoflagillates are abundant all year round, and shine brightest on nights following bright sunny days. They are also best viewed on the darkest nights when there is little to no visible moon in the sky.

When is the best time to visit?

 Insider Tip:  For the best viewing conditions plan your trip on the DARKEST nights when there is VERY LITTLE, TO NO VISIBLE MOON in the sky. The darker the night sky the brighter the lights.

• Moon Phase Calendar