'BA' (i) was the designation of Allied convoys (together with a numerical and sometime a literal suffix) plying the route between Bombay, India, and any of the ports in the Red Sea, but most notably Aden, and as such reciprocals of the 'AB' series (February 1941/September 1944).

The first of this 'Bombay to Aden' series was BA.1 which departed Bombay on 20 February 1941 with the 11,898-ton British President Doumer carrying 815 troop and stores, 7,936-ton British Takliwa carrying 907 troops and stores, and 4,701-ton British Varsova carrying 855 troops and stores, with escort provided by 11,174-ton British armed merchant cruiser Antenor. The last of the series was BA.78A of 14/21 September 1944 with the 5,108-ton British Ekma and 10,000-ton British Talma escorted by the British sloop Shoreham and Australian minesweepers Cairns and Wollongong.