After the Armistice, the ship was initially placed in reserve at Devonport but soon joined the Atlantic Fleet, with a particular role as an escort to the aircraft carriers Courageous and Furious.

[1] The design was generally similar to the preceding M class, but differed in having geared steam turbines, giving greater fuel efficiency, the aft gun mounted on a raised platform, a higher forecastle for better seakeeping and a larger and a more robust bridge structure.

A total of 296 long tons (301 t) of fuel oil was carried, which gave a design range of 3,450 nautical miles (6,390 km; 3,970 mi) at 15 knots (28 km/h; 17 mph).

[5] Armament consisted of three single QF 4 in (102 mm) Mk IV guns on the ship's centreline, with one on the forecastle, one aft on a raised platform and one between the second and third funnels.

Between 16 and 17 October 1917, the destroyer was called upon to be part of a large force of 84 warships sent out to search for a German fleet based around a minelayer, although Tetrarch saw no action.

[10] The destroyer joined sister ship Tempest in the First Ostend Raid, accompanying monitors Erebus and Terror that led the attack on 23 April 1918.

[13][14] After the Armistice of 11 November 1918 that ended the war, the Royal Navy returned to a peacetime level of strength and both the number of ships and personnel needed to be reduced to save money.

[21] The vessel was back in the Mediterranean Sea visiting Malta on 14 March the following year before, on 5 September, taking part in exercises off the coast of Scotland with the fleet, including the Third Battle Squadron and a flotilla of battlecruisers led by HMS Hood.

[25] The destroyer then undertook a tour of seaside resorts, visiting Milford Haven, St Ives and Dover between 9 June and 21 July.