Bangla Channel Swimming

The sea passage off Teknaf hosts the Bangla Channel Swimming, an open water marathon swim across the sea passage off Teknaf in the Cox's Bazar district of Bangladesh. Setting out from the mainland edge to cross this channel means undertaking one of South Asia's most demanding endurance challenges, where swimmers take on the open sea under their own power. The charted crossing is a 16.1-kilometre sea passage connecting the western shore of Shahporir Island to the northern sands of Saint Martin. Organized by Shoroj Adventure under the Ministry of Youth and Sports, the course represents the gold standard of Bangladeshi marathon swimming. The route was first established on January 14, 2006, by Hamidul Haque, who pioneered the line when swimmers completed the inaugural crossing.

In those early seasons between 2006 and 2011, participants swam a shorter line of 14.4 kilometres using fins and snorkels to negotiate the currents. The event came of age in 2012 when organizers lengthened the official distance to 16.1 kilometres and transitioned the channel to standard open water swimming rules. The ultimate benchmark on this stretch of water came on December 15, 2019, when Tahrina Nasrin achieved the first two-way crossing of the 32.2-kilometre channel by a woman, touching both shores and returning in 8 hours and 13 minutes. At the water's edge, entering the sea demands immediate focus. Near the starting shore, swimmers can meet breaking waves, so the entry calls for careful timing to dive beneath the breakers and gain deep water.

Once past the surf zone, the crossing settles into a rhythmic journey over open oceanic swells. Every athlete is accompanied throughout the crossing in accordance with international safety standards, with a dedicated support boat and rescue personnel tracking alongside each swimmer from beach to beach. That constant escort allows swimmers to focus entirely on their pacing, knowing that professional support is watching every arm stroke until they touch Saint Martin.

The Naf River estuary and the Bay of Bengal

The channel flows directly across the massive estuary where the Naf River discharges its flow into the Bay of Bengal, marking the coastal divide between the Cox's Bazar District in Bangladesh and Rakhine State in Myanmar. Both Shapuree Island at the starting point and Saint Martin's Island at the finish sit positioned squarely at the wide mouth of this tidal river system. Underneath the swimming line, the underwater landscape drops away into formidable depths.

Shah Porir Dwip: the sentinel of the Anglo-Burmese frontier

The departure point sits at the absolute southern tip of mainland Bangladesh, where the upazila of Teknaf tapers into the sea. Shah Porir Dwip is itself a natural geographical extension of this narrow peninsula, pointing like a finger into the channel toward Saint Martin. In geological terms, Saint Martin's Island was once part of this same mainland peninsula before ancient inundations by the Bay of Bengal separated the landmass, leaving the channel that athletes swim across today. This low-lying coastal sentinel also carries significant historical weight along the maritime frontier. In the early nineteenth century, the British claimed Shapuree Island, turning the outpost into a contested flashpoint that ultimately helped trigger the outbreak of the First Anglo-Burmese War. Long before becoming a proving ground for marathon swimmers, this narrow strip of land served as a strategic military border and a watchpost over the maritime straits.

Saint Martin's Island: the coral sanctuary and marine park

Emerging at the northern beach of Saint Martin's Island brings swimmers onto the only coral island in the whole of Bangladesh. To safeguard its unique marine environment from ecological strain, the surrounding waters were formally designated as a Marine Protected Area in 2022. The sanctuary status was designed to preserve this delicate offshore environment and protect what remains of the reef ecosystems, which suffered the loss of 70 percent of their living coral coverage between 1980 and 2018 due to human pressures. The open channel between the Teknaf Peninsula and the island serves as a vital feeding area for marine megafauna, regularly hosting resident dolphins, porpoises, numerous threatened fish species, and circling seabirds. Swimming here means sharing the surface with rich pelagic wildlife that thrives in this productive marine crossroad.

The shores of Teknaf: mangroves, dunes and fishing craft

Teknaf Beach is bordered by the dense mangrove swamps of the Teknaf peninsula, which give way to distinct beaches including Shamlapur, Shilakhali, Hajampara, and Shapuree Island Beach. Backing these sandy shores are the deep greenery of Zhaoban forests and the rugged ridge of the Tainga hills rising to the north, framing the launch point in wild coastal scenery. Along the water's edge, brightly painted fishing boats rest pulled up on the sand, waiting for the tides that define daily life along the coast. Out in the channel, Saint Martin's Island breathes with those same tidal rhythms: at high tide its exposed land shrinks from eight square kilometres down to just five square kilometres as the sea claims the flats. Reaching that shifting shore after battling through miles of open surf brings an unforgettable sense of achievement, stepping out onto the sand having conquered the channel by the sheer strength of your own arms.