[4] She was involved in a collision with her sister ship, Redpole, on 7 March 1911, and took part in the Coronation Fleet Review on 24 July 1911.

[6] On the outbreak of the First World War in August 1914, the 2nd Destroyer Flotilla, including Acorn joined the newly established Grand Fleet.

[12] In a friendly fire incident on 20 June 1918, she opened gunfire on the U.S. Navy submarine chaser USS SC-151 in the Strait of Otranto.

[13] Acorn remained part of the Mediterranean Fleet at the end of the war in November 1918, when she was serving in the Aegean Squadron, based at Mudros.

[14][15] Acorn was in reserve at Devonport Naval Base in March 1919,[16] and was sold for scrap to Marple & Gillot of Saltash on 29 November 1921.