A few photographs taken on a small island in the Maldives turned one beach into a bucket-list destination almost overnight. They showed waves breaking in glowing blue along the shore, as if the sea were full of stars. That beach is on Vaadhoo, a local island in Raa Atoll, and the images are a big reason so many people now search for “Maldives bioluminescent beach” before booking a trip. The phenomenon is real, but it is not a permanent fixture, and Vaadhoo is far from the only place where it happens. This page explains what causes the glow, when and where you are most likely to see it, and how to set realistic expectations. For the wider topic, see our guide to bioluminescent beaches.

Vaadhoo and the “Sea of Stars”

Vaadhoo is a small inhabited island in Raa Atoll, in the northern Maldives. It became famous after photographs of its glowing shoreline spread online in the mid-2010s.

Those long-exposure images, with blue-lit waves under a starry sky, were shared around the world and gave the beach its nickname. Since then, “Sea of Stars” has become a common name for the glowing water of the Maldives in general. Vaadhoo is a local island rather than a resort, so travellers visiting specifically for the glow usually stay in local guesthouses or arrange a trip from a nearby resort.

It is worth stressing that the glow is not a permanent feature of one beach. It depends on plankton being washed into the shallows, and that depends on currents, winds, water temperature and nutrients. Some visitors see a spectacular display on their first night; others spend a week on the island and see nothing. The same is true of glowing beaches everywhere.

What makes the beach glow

The light is bioluminescence, made by living organisms through a chemical reaction. In the Maldives two main kinds of plankton are usually credited. The first is dinoflagellates, single-celled plankton that flash when the water around them is disturbed. When a wave breaks or a foot splashes, the pressure change triggers a reaction inside each cell in which the enzyme luciferase acts on a molecule called luciferin and releases a burst of blue light. Billions of cells flashing at once outline the wave in light. Our bioluminescent plankton page explains this in more detail.

The second is ostracods, also called seed shrimp. These are tiny crustaceans, about the size of a sesame seed, enclosed in a two-part shell. Some species release a cloud of glowing chemicals into the water when disturbed, and in the Caribbean and Pacific some males use light displays to attract mates. Ostracod light tends to appear as brighter, longer-lasting dots and smudges rather than the instant flash of dinoflagellates. In photos of Maldivian beaches, both kinds of light may be present.

Why do plankton glow at all? For dinoflagellates, the leading explanation is the “burglar alarm”: a grazer that tries to eat them gets lit up, which attracts the grazer’s own predators. For ostracods, the glowing clouds are thought to startle or distract predators, much like a squid’s ink.

When the glow is most likely

There is no fixed season, but most reports from the Maldives cluster in the second half of the year, roughly from mid-year into early winter. This period overlaps with the southwest monsoon and the transition that follows it, when winds and currents shift and can push plankton toward particular shorelines. Warm water and nutrients brought by changing currents can also boost plankton growth. Even within that window, sightings are patchy and can vary from island to island and night to night.

Whatever the month, three conditions make the biggest difference. The first is darkness: a new moon or a moon that rises late, and a stretch of beach away from resort lighting. The second is gentle surf; small waves breaking right on the sand light up best. The third is simply luck with the plankton. If you are staying at a resort, ask the staff or dive centre whether anyone has seen it recently. They are usually the first to know.

Other islands where it happens

Because the glow depends on plankton rather than on a particular beach, it has been reported on many islands across the Maldives, including resort islands in Baa, Raa, Lhaviyani and other atolls. Some resorts have built a reputation for frequent sightings and will alert guests when the beach lights up. Rather than planning an entire trip around Vaadhoo, it makes more sense to stay somewhere with a long, dark stretch of beach and keep an eye on the water each night.

The same phenomenon also turns up far from the Maldives: on beaches in California, Australia, Thailand, Taiwan’s Matsu Islands, Puerto Rico and elsewhere. For a comparison of the main glowing destinations, see bioluminescent beaches. If you want a near-guaranteed glow, enclosed bays such as Jamaica’s Luminous Lagoon are far more reliable than open beaches.

Photographing the glow

Most of the dramatic images of the Maldives’ Sea of Stars are long exposures, often several seconds or more, taken on a tripod and sometimes combined or edited. Each flash of bioluminescence lasts only a fraction of a second, so a long exposure adds up many flashes into a single bright streak. To the eye, the glow usually looks softer and more fleeting than in those photos. That doesn’t make it any less beautiful, but it is worth knowing before you go.

If you want to try, use a camera that allows manual settings, a sturdy tripod, a wide-aperture lens and a high ISO. Turn off the flash and avoid using a torch; any artificial light will overwhelm the faint blue. Phone night modes can capture something on a bright night, but rarely what you see.

Is it safe to touch or swim in?

The plankton responsible for most glowing beaches are not harmful to touch, and many people wade or swim in the glowing surf. A few dinoflagellate species can produce toxins during blooms elsewhere in the world, and very dense blooms can irritate the skin or eyes of sensitive people, so it is sensible not to swallow the water and to rinse off afterward. Normal beach safety applies at night too: currents around Maldivian islands can be strong, especially near channels, and reef edges can be sharp. Swimming alone in the dark is never a good idea.

The reefs behind the beaches

The Maldives is made of coral. Its roughly 26 natural atolls and more than a thousand islands are built on reefs that grew on top of an ancient volcanic ridge. Those reefs support the plankton, fish and coral that make the Maldives one of the world’s great diving destinations, and they are also what make the beaches so white. Our pages on types of coral reefs in the Maldives and Maldives coral reef maps cover how the atolls are built. The reefs are also vulnerable: warming seas have caused repeated mass coral bleaching events there; see Maldives coral reef bleaching.

My advice on chasing the Sea of Stars

I haven’t dived the Maldives myself, but I’ve kept reef systems since 1996 and dived reefs from the Caribbean to the Pacific, and the advice I would give is the same I give about any natural spectacle: plan for the place, not the photo. If I were heading to the Maldives hoping to see glowing waves, I would choose an island with a long, dark beach, check the moon calendar so at least part of the stay falls near the new moon, and ask locally every day whether the plankton have appeared. I would treat the glow as a bonus, not the purpose of the trip.

The Maldives has plenty to offer even if the beach never lights up: manta rays, whale sharks, reef sharks and some of the clearest water in the Indian Ocean. And if you do see the Sea of Stars, you will know you were lucky, which is part of what makes it special. For more on what lights up the water, see our pages on sea sparkle and bioluminescence.