As of Jun 19, 2026, 8:54 PM, out of season, returns ~November. Earth Exhibit tracks the live conditions and flags it the moment it is on.
On dark, moonless nights off Phú Quốc — Vietnam's island in the Gulf of Thailand — the shallow sea can flash with cold blue light wherever it is stirred.
The glow comes from dinoflagellate plankton (usually Noctiluca scintillans) that emit a brief blue spark when the water around them is disturbed: a paddle stroke, a breaking wavelet, or a foot kicked through the shallows lights up in trails and sheets of blue.
The island's local night squid-fishing tours are the classic way to see it — boats run out after sunset, and the same calm, dark conditions that make for good squid fishing also reveal the plankton in the bow wave and around the boat.
From the quieter beaches you can sometimes see it straight from the shoreline, throwing water into the air to watch it glow.
It is not on every night — the plankton come and go with water temperature, currents and bloom density — and it shows only when the sky is dark and the moon is down, away from the resort lights of the busier coast.
Where to see it
A taste of where to see it. The full map, exact coordinates and the best timing for each spot live in the app.
| Viewing spots |
|---|
| Ông Lang Beach |
| Rạch Vẹm Fishing Village (Starfish Beach) |
| + 2 more spots, with exact coordinates and timing, in the app → |
This is the short version
This page shows a taste. The app has the full list of where to see this, the exact timing, and live conditions for 1,000+ natural phenomena worldwide, so you know the moment one is genuinely worth the trip.