On 16 March 1915, Watson gained his Royal Aero Club Certificate No. 1,117 (equivalent of a pilot's licence) with the London and Provincial School at the London Aerodrome, Hendon, having sought a commission with the Royal Naval Air Service with the outbreak of war in 1914. Sadly, on 30 June 1915 he lost his life when the Caudron G.3 aeroplane he was flying disintegrated in flight and crashed in Dunlye field, a few miles from the Cross-in-Hand Hotel, Sussex. Watson is buried in Dundee's Western Cemetery.