The Bay of Bengal is a large, triangular embayment forming the northeastern part of the Indian Ocean, and is recognized as the world's largest bay. It is bordered by India and Sri Lanka to the west, Bangladesh to the north, and Myanmar and the Andaman and Nicobar Islands of India to the east. The bay covers an expansive area of approximately 2.17 million square kilometers and has an average depth of about 2,600 meters.
Historically, the Bay of Bengal served as a natural bridge connecting the Indian Subcontinent with regions to the east, facilitating the movement of people, goods, and ideas, including the spread of Hindu and Buddhist influences. Its significance is deeply rooted in its geography, as it is the outlet for major river systems of the Indian subcontinent, including the Ganges, Brahmaputra, Godavari, Krishna, and Mahanadi. These rivers create the world's largest delta, the Sundarbans, and deposit vast amounts of sediment, forming the Bengal Fan, the largest submarine fan globally.
The bay's mechanism is crucial to the region's climate, as it is the cradle of the South Asian summer monsoon and a principal genesis basin for tropical cyclones, which form mainly during the pre-monsoon (April–May) and post-monsoon (October–November) seasons. Geopolitically, the Bay of Bengal is a vital component of the emerging Indo-Pacific concept, linking the Indian Ocean to the western Pacific via the critical Strait of Malacca. It connects to the regional institution, the Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC), founded in 1997, which serves as a platform for cooperation among seven South and Southeast Asian countries. India's engagement in the bay is central to its Act East Policy and SAGAR (Security and Growth for All in the Region) framework, aiming to project itself as a net security provider and leader of regional connectivity. The bay has also been an arena for legal settlement, notably the Bangladesh v. Myanmar (2012) judgment by the International Tribunal for the Law of the Sea (ITLOS), which delimited their maritime boundary under the UN Convention on the Law of the Sea (UNCLOS, 1982).