Air commodore is never shortened to Commodore, which is a rank in various naval forces. Air commodore is a one-star rank and the most junior air officer rank, being immediately senior to group captain and immediately subordinate to air vice-marshal. It has a NATO ranking code of OF-6 and is equivalent to a commodore in the Royal Navy or a brigadier in the British Army or the Royal Marines. Unlike these two ranks, however, it has always been a substantive rank. Additionally, air commodores have always been considered to be air officers whilst Royal Navy commodores have not since the Napoleonic Wars
William Kerr (Royal Navy officer) William Kerr (Royal Navy officer) Commodore The Hon. William Kerr was a Royal Navy officer who served as Commander-in-Chief of the Jamaica Station. Born a younger son of the Earl of Lothian, Kerr was promoted to post captain on 14 May 1690 on appointment to the command of the fourth-rate HMS "Deptford". He transferred to the command of the fourth-rate HMS "Burlington" in 1696, of the third-rate HMS "Lenox" later the same year and of the third-rate HMS "Eagle" in 1700. He went on to receive the command the third-rate HMS "Revenge" in 1702. Promoted to Commodore, Kerr became Commander-in-Chief