Military Wiki
John Saumarez Dumaresq
Rear Admiral John Dumaresq
Born (1873-10-26)October 26, 1873
Died July 22, 1922(1922-07-22) (aged 48)
Place of birth Sydney, Australia
Place of death Manila
Allegiance  United Kingdom
Service/branch  Royal Navy
 Royal Australian Navy
Years of service 1886 – 1922
Rank Generic-Navy-O9.svg Rear Admiral
Commands held HMS Shannon (1913)
HMAS Sydney (February 1917)
Commodore commanding Australian fleet (22 March 1919)
Battles/wars World War I
*War at Sea
*Battle of Jutland
*Action of 4 May 1917
*Third Battle of Heligoland Bight
Awards Companion of the Order of the Bath
Commander of the Royal Victorian Order

Rear Admiral John Saumarez Dumaresq CB, CVO (/dʉˈmɛərɨk/ duu-MAIR-ik;[1] 26 October 1873 – 22 July 1922) was an officer in the Royal Navy. He served during World War I but is most remembered as an inventor, for development of the device named after him, the Dumaresq, which helped users calculate the rate at which the range to an enemy ship was changing over time. He was the first Australian born officer to command the Royal Australian Navy.


Dumaresq was the grandson of a British settler who had originally gone to Australia accompanying the Governor of New South Wales Ralph Darling in 1825. In 1907 he married Christian Elizabeth Louisa Dalrymple.

He lived in England from age two and became a naval cadet at HMS Britannia in 1886. He became interested in torpedoes and gunnery and introduced a number of innovations. In 1904 he was promoted to Commander. In 1908 he commanded a flotilla escorting King Edward VII on a tour of Russia and received the MVO from the King and Order of Saint Catherine from the Tsar. On 30 June 1910 he was promoted to captain, working on fire control equipment at the Royal Navy war college at Portsmouth.

In 1913 he became captain of HMS Shannon and took part in the Battle of Jutland. He was appointed to the Order of the Bath (CB) for his part in the battle

In February 1917 he was appointed commanding officer of HMAS Sydney, which was serving as part of the Grand Fleet in the North Sea. Shortly afterwards, the ship and its accompanying patrol were involved in an attack by a Zeppelin. Dumaresq attempted to trap the Zeppelin by ordering the accompanying ships to disperse, leaving the Zeppelin attempting to bomb his ship and coming closer, and then ordering them back forming a ring surrounding the enemy. The Zeppelin remained too high, meaning the ships' anti-aircraft guns could not reach it, but also the Zeppelin could not aim reliably enough to drop bombs on the ships below.

Dumaresq became convinced of the need for aircraft to operate from ships and a platform to his design was installed on Sydney in October 1917 for the purpose of launching an aeroplane. During an engagement with enemy destroyers at Heligoland Bight on 1 June 1918, the aircraft was used in action to drive off two attacking German aeroplanes, shooting down one.

Dumaresq was appointed Commodore commanding the Australian fleet on 22 March 1919, as the first Australian born officer to do so. His flagship then became HMAS Australia. Ships of the Australian navy had been distributed around the world during the war, but now returned to Australian waters based at Sydney. His period of command was marked by disagreement with the Australian government over expenditure upon the navy. In 1920 be received the CVO and in June 1921 was promoted to Rear-Admiral.

In April 1922 he was posted back to the Royal Navy. On the return journey he contracted pneumonia, and died in the US Military Hospital in Manila on 22 July.


  1. G.M. Miller, BBC Pronouncing Dictionary of British Names (London: Oxford UP, 1971), p. 48.

External links

Military offices
Preceded by
Rear Admiral Sir Lionel Halsey
Rear Admiral Commanding HM Australian Fleet
1919 – 1922
Succeeded by
Rear Admiral Albert Addison

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