For secondary armament, the destroyer was equipped with a single QF 2-pounder "pom-pom" Mk.II and four 21-inch (533 mm) torpedo tubes in two twin mounts.

[2] As a Thornycroft "special", Patriot resembled the standard Admiralty version of the class with the exception of her flat-sided funnels and higher freeboard.

[1] Patriot was one of two Thornycroft M-class destroyers ordered in February 1915 as part of the Fourth War Construction Programme, along with 15 of the standard Admiralty design.

[4][5] In early July 1917, Patriot took part with another five destroyers (the leader Anzac, together with Norman, Maenad, Morning Star and Moon) in a mission against German submarines transiting the North Sea.

The patrol made several sightings of a submarine, but did not manage to bring it to action before a shortage of hydrogen for the balloons on 8 July forced the flotilla to return to Scapa Flow.

[8][note 1] In October 1917, Patriot formed part of a large-scale operation, involving 30 cruisers and 54 destroyers deployed in eight groups across the North Sea in an attempt to stop a suspected sortie by German naval forces.

Despite these countermeasures, the two German light cruisers Bremse and Brummer, managed to evade the patrols and attacked the regular convoy between Norway and Britain, sinking nine merchant ships and two destroyers, Mary Rose and Strongbow before returning safely to Germany.

[18][19] Patriot, Patrician and the cruiser Aurora were commissioned into the Royal Canadian Navy on 1 November 1920 at Devonport and departed for Halifax, Nova Scotia one month later.

[22] Roughly once a year, Patriot sailed to the West Indies to take part in naval exercises with the Royal Navy.