Swallow Reef

Swallow Reef is a coral atoll in the South China Sea, located roughly 300 kilometers northwest of the Sabah coast. The lagoon inside is encircled by coral banks that become partly visible at low tide and lie below the water surface at high tide.

Malaysia built a military station on the reef in 1983 and began land reclamation to expand its footprint. Infrastructure grew over the following decades, allowing a permanent presence on the atoll.

The name recalls the swallows once seen here before the island took on its current military and tourism functions. Divers and visitors can watch the colony of crested terns nesting on the coral banks, cycling through different breeding phases throughout the year.

Visitors arrive via the small airstrip served from Kota Kinabalu, which provides access to the research station and dive sites. Weather conditions in the South China Sea can change quickly, so plan for flexible travel schedules and limited supply options on site.

The research station MARSAL conducts studies on marine biodiversity while hammerhead sharks appear near the reefs during certain months. Divers report that the sharks often move through the deeper channels in small groups, making the atoll a draw for underwater observation.