Saint Martin's Island

Saint Martin's Island is Bangladesh's only coral island, a small landmass of roughly three square kilometres in the northeastern Bay of Bengal, nine kilometres south of the tip of the Cox's Bazar-Teknaf peninsula and forming the southernmost point of Bangladesh.

It was, millennia ago, an extension of the Teknaf peninsula, but the sea claimed the connecting land and left the southern tip isolated, a process of geological change that continues today: the island is slowly being eroded by wave action, and its size has measurably decreased over the past century as storm surges and rising sea levels accelerate the coastal erosion that is reshaping coastlines across the Bay of Bengal.

The island is made of coral limestone and dead coral, the skeleton of ancient reef-building organisms that died and accumulated over thousands of years, and at low tide the reef that surrounds it is exposed as a white limestone shelf with tidal pools full of small fish, hermit crabs and shells that children collect and sell to visitors.

The coral is not the vivid multicoloured reef of the Maldives or the Great Barrier Reef — the species diversity is lower and the colours are more muted, dominated by brain corals and staghorn varieties in shades of brown and green — but the fact of coral formation at this latitude, this far from the equator, in the Bay of Bengal, is itself remarkable and worth the journey.

St. Martin's supports a small resident fishing community whose members have lived on the island for generations, and the island has become a major domestic tourism destination, particularly in the winter months when the sea is calm and the weather is dry and clear and the crossing from the mainland is safe.

The island has been subject to a nine-month tourist restriction beginning February 2025, a response to environmental pressure from visitor numbers that were overwhelming the island's carrying capacity and damaging the coral reef and the island's fresh water lens, a subsurface layer of fresh water that floats above the denser salt water and is the only source of drinking water for the islanders.

The ferry from Chittagong or Cox's Bazar to Saint Martin's is itself a significant experience: the Bay of Bengal in the monsoon season can be rough, and the crossing takes several hours in open-deck boats, but on a calm day the approach to the island reveals a flat green strip on the horizon with the white of the breaking reef all around it, quite unlike anything else in Bangladesh.

Saint Martin's is Bangladesh's only coral island and its southernmost point, offering a combination of marine landscape, coral reef and island atmosphere that is genuinely unique in the country.

The journey by ferry across the Bay of Bengal is itself a memorable experience, and the approach to the island from the water is unlike any other coastal view in Bangladesh.

The 2025 tourist restriction is an indicator of the island's ecological fragility — visiting responsibly, outside the restricted season, and with awareness of the fresh water lens issue, is part of what makes the trip meaningful.