Koh Losin Through My Lens

Koh Losin Through My Lens

“Imagine a tiny rock outcrop, merely 50 square meters,

rising above the deep blue waters

in the middle of the Gulf of Thailand so isolated

that most people don’t even know it exists.”

To many, it might seem like just a small dot on a map. Though for a diver like me, “Koh Losin” is an underwater paradise featuring a seascape unlike anywhere else on Earth.

By international maritime law, Losin possesses an immense geopolitical and economic importance far beyond its physical size. This is because Losin serves as the baseline for Thailand’s continental shelf and Exclusive Economic Zone (EEZ) claims.

Koh Losin is the smallest limestone islet in Thailand, located in Ban Nam Bo Subdistrict, Panare District, Pattani Province. Situated about 80 kilometers offshore near the Thai-Malaysia border, a passing glance from a boat might make you think it is nothing but a small light house. If you dive beneath the surface, however, you will discover one of Thailand’s invaluable oceanographic treasures.

To me, this islet is like the “Oasis of the Gulf of Thailand.” Its richness stems from a unique underwater topography: an isolated limestone pinnacle rising sharply from the ocean floor. This forms a natural barrier against deep-sea currents, triggering a process known as “upwelling,” which carries nutrient-rich water from the depths to the surface. These nutrients nourish a thriving reef ecosystem with immense biodiversity, turning it into a gathering spot for “giants of the sea” like whale sharks, which stop by to feed and visit cleaning stations. It is no surprise that my fellow divers and I can encounter two or three of them at the same time.

The colorful range of Staghorn coral (Acropora) found at Koh Losin that seems to stretch past the far horizon. These corals provide vital structural complexity for the island’s rich marine biodiversity, though its branches are thin and fragile, making them vulnerable to physical destruction.
A visual diagram showing how upwelling brings nutrients like phytoplankton and zooplankton towards the surface.

Beyond the whale sharks, another charm that made me fall in love with Koh Losin is its signature deep-blue water, so clear that visibility exceeds 30 meters. This clarity opens up breathtaking views of endless fields of staghorn coral (Acropora). And as the sun dips below the horizon, these waters come alive with sea slugs showcasing themselves throughout the dark.

A dense school of bigeye trevally (Caranx sexfasciatus) navigating the shallow waters surrounding the Koh Losin pinnacle.
A green sea turtle glides gracefully through the deep blue waters of the open ocean around Koh Losin, showcasing the clarity found far from the mainland. Shot during a safety stop, this image symbolizes the vast abundance of life around these waters.

Tragically, that beauty is turning into a memory. Returning to dive at Koh Losin every year since 2021, I have noticed the once-vibrant reef suffering increasingly from coral bleaching, exacerbated by relentless human threats. One devastating incident occurred in mid-2021 when a massive 2,750-square-meter “ghost net,” discarded by reckless fishing boats, drifted down and draped over the reef. Although Navy officials and volunteer divers managed to salvage it, the 800-kilogram net crushed over 500 square meters of staghorn coral to pieces.

A diver witnesses the devastating reality of global warming firsthand, documenting a severe coral bleaching event that has reduced a massive reef structure of its life and color.
Captured during a night dive, the image highlights the contrast between Koh Losin’s remaining megafauna and its struggling benthic habitat. While large pelagic and reef fish continue to utilize the pinnacle as a critical feeding ground, the background reveals a severely bleached coral colony and a fragmented bed of dead staghorn rubble.
High habitat complexity supports ecological resilience at Koh Losin. Despite thermal stress affecting select colonies, the expansive structural framework of the staghorn reef remains intact and actively supports massive aggregations of marine life, as seen in the background. This high density of swarming fish provides the balance needed to recover the reef, demonstrating that there is still hope.

To me, Losin is not just a dive site; it is a sanctuary for my soul, a place to escape the chaos of urban life. Yet today, the passion and connection I once felt are replaced by heartbreak every time I submerge. The wonder of yesterday is slowly swallowed up, transformed into a coral graveyard that continues to expand at a devastating rate.

The underwater coral graveyards at Losin serve as a direct reminder that nowhere on Earth is safe from human greed and selfishness. If we continue to look the other way and allow nature to be continually abused, it won’t be long before this underwater paradise meets the same tragic fate as many other reefs that have collapsed before it.

Discover more Tinnapat’s work here 

Story and photography by Tinnapat Netcharussaeng

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