Sidney Watson was born in Colchester, Essex on 15 May 1893, the son of Colonel Solomon Watson and the Hon. Elsnith Georgina Isobel de Beauchamp Watson (née Roper-Curzon). He joined the Royal Navy as a Cadet on 15 May 1906 and was promoted to Midshipman on 15 January 1911. Sidney Watson was appointed to the battleship HMS ZEALANDIA on 16 February 1914 and promoted to Sub Lieutenant on 15th March 1914.

He was next appointed to the Submarine Depot Ship HMS VULCAN (Seventh Submarine Flotilla) at Leith ‘for Submarines’ to date 13 November 1914. He served in HMS C23 before he was further appointed to HMS C20 as First Lieutenant on 16 May 1915 then to HMS E5 as First Lieutenant was 10 February 1916. Sidney Watson died when E5 was lost on 7 March 1916.

Lieutenant Sidney Watson is commemorated on the Portsmouth Naval War Memorial Panel No 11.