Saint Martin's is the only open-sea island Bangladesh has, a sliver of sandstone under coconut palms at the country's southern tip, and for most of the year it is now shut. It was an overlooked fishing island until 1990, when a novel called Daruchini Dwip, Cinnamon Island, sent a generation of Bengali readers looking for it. Plenty of them still call the island by that name. What they arrived on has almost no fresh water of its own. The island drinks from a shallow layer of rain-fed groundwater sitting on salt water, and hotels and homes drew it down faster than the rains replaced it. Seawater pushed in behind, surges flooded the rest, and several wells have gone brackish. Since the 2024-25 season visitors are allowed only in a short window; the island keeps to itself the other nine months.
The boats are the first thing you see. They are narrow, high-prowed and painted in bands of red, yellow and blue, and they come straight up onto the sand rather than tying to a pier. The early hours belong to crews sorting the night's catch. Twice a day the sea pulls back off a wide plain of dark, rounded sandstone pooled with trapped water, and the rock carries a thin living crust of coral. That crust is all of it you get. The belief that this island has a coral reef runs so deep that scientists have had to publish formal corrections to papers that valued one. The rock is sandstone and conglomerate; corals merely settle on it, conditions being too marginal for them to build a framework of their own. It is still the only place in the country where you can float above living coral. Chhera Dwip, at the far end, joins the island only at low water, two hours out over sand and slick boulders, the tide closing the way behind you as fast as in front. Nobody lives there. The sand simply stops, and the country stops with it — while back on the island people carry their drinking water a kilometre or more.