The International Tribunal for the Law of the Sea (ITLOS) established the maritime boundary between Bangladesh and Myanmar on 14 March 2012. In the territorial sea, the Tribunal used the equidistance methodology, giving full effect to Bangladesh’s St. Martin’s Island until the line reached the 12 M territorial sea limit. From this point, the boundary then followed the territorial sea limit forming a semi-enclave around St. Martins Island. The line proceeded along the 12 M limit until it reached the mainland to mainland equidistance line on the seaward side of the island.

The boundary in the exclusive economic zone was delimited using a modified equidistance line giving no effect to St. Martin’s Island and then following a directional azimuth that would help to mitigate the cutoff effect for Bangladesh caused by the severe coastal concavity in the northern reaches of the Bay of Bengal. The Tribunal finally extended the border beyond the Parties’ 200 M EEZ limit, into the outer continental shelf, where both States have ECS claims.