[1] Greater speed was wanted to match large fast destroyers building for foreign navies, while a larger radius of action was desired.

[7] The ship was fitted with a 2-pounder "pom-pom" anti-aircraft autocannon during the First World War, while in 1918 the torpedo tubes and one of the 4-inch guns was removed to allow a heavy depth charge armament to be carried.

[14][15] On the outbreak of the First World War in August 1914, the 4th Flotilla, including Achates, became part of the Grand Fleet based at Scapa Flow in Orkney.

[15][16] On 25 October 1914, Achates, together with Ardent, Ambuscade and Fortune, escorted the Second Battlecruiser Squadron when it sailed in support of an unsuccessful raid by seaplane carriers and the Harwich Force against airship sheds at Cuxhaven.

[18] On 13 February, Achates was one of seven destroyers from the 4th Flotilla ordered to patrol in the North Channel between Northern Ireland and Scotland as a result of attacks by the German submarine U-27.

[19] Achates was under refit on 24 April 1916, and so did not take part in the Grand Fleet's sortie in response to the German Bombardment of Yarmouth and Lowestoft.

The flotilla leader Tipperary was badly damaged by German shells (mainly from the battleship Westfalen) and later sank, while the leading ships in the British formation fired a total of nine torpedoes, none of which hit.

Broke was badly damaged by fire from the cruiser Rostock and Westfalen, and collided with the destroyer Sparrowhawk, which was also rammed by Contest and was later scuttled.

[27] In order to counter German minelayers and to protect British minesweepers in the North Sea, the 4th Flotilla, including Achates, transferred to Immingham on the Humber estuary at the end of July 1916.

[33][34][29] On 16 December 1916 Achates was patrolling with Owl and Contest off The Lizard when they received a report of a German submarine (actually UB-38) attacking shipping off the Cornish coast.

[37] On 24 May 1917, Achates was on patrol off Berry Head, Dorset, when gunfire was heard and the destroyer investigated, sighting the fishing vessel Competitor, which had been fired upon by the German submarine UB-38, and whose crew had abandoned ship.

[39] On 6 July 1918, Achates was one of six destroyers escorting the Atlantic convoy HH.4, inbound from the Hampton Roads, when the oiler SS Wabasha was torpedoed by the German submarine UB-32.