Bay of Bengal

The Bay of Bengal is the expanse of water bordered by the present-day countries India, Myanmar (Burma), Thailand (Siam) and Malaysia and during the First World War. It was a focus of naval operations in the Indian Ocean during the First World War because the major sea lanes between Australia and the East Indies and Europe and the Middle East crossed its mouth. The bay was also a busy seaway in its own right, frequented by Allied vessels calling at ports in India, Myanmar and Thailand. Between September and October 1914 the German cruiser SMS Emden wrought havoc in the Bay of Bengal necessitating a large Allied naval presence there. The direct naval threat to shipping in the Bay of Bengal declined by the end of 1914 but throughout the war there always remained the possibility of German commerce raiders stalking the shipping routes.

An additional threat materialised during 1915 when intelligence was received indicating German plans to smuggle arms into India and Burma and thereby foment revolt. Shipping in the bay was heavily controlled during the latter half of 1915, and vessels of all sizes were stopped and searched on a wide scale. No arms or German raiding parties were ever intercepted and the Australian official historian described the "whole proceeding" as being "petty" and that there was "more excitement about arresting a pickpocket". The threat had passed by the beginning of 1916 and most ships involved in the patrols operations were relocated.