[2][4] Vanoc reached an average speed of 32.083 knots (59.418 km/h; 36.920 mph) during sea trials on 10 August 1917, with her engines generating 28,136 shaft horsepower (20,981 kW) and deep load displacement about 1,430 long tons (1,450 t).

[5] The ship carried 368 long tons (374 t) of oil giving a range of 3,500 nautical miles (6,500 km; 4,000 mi) at 15 knots (28 km/h; 17 mph).

[17] The long-range escort conversion involved removal of one boiler (and its associated funnel), to allow fitting of additional oil bunkers and extra accommodation to help solve a chronic overcrowding problem that had only got worse as crews had increased as the war progressed.

[18] While power dropped to 18,000 shaft horsepower (13,000 kW), cutting speed to 24.5 knots (45.4 km/h; 28.2 mph), the ship's range increased by as much as 600 nautical miles (1,100 km; 690 mi).

[18][19] Following commissioning, Vanoc joined the Thirteenth Destroyer Flotilla, attached to the Battle Cruiser Force of the Grand Fleet.

[20][21][22] In October 1917, Vanoc was 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.

[22] On 29 June 1927, Vanoc, together with Wrestler, Tilbury and Toreador escorted the battlecruiser HMS Renown, carrying the Duke and Duchess of York into Portsmouth at the end of the royal couple's tour of the Commonwealth.

[39] At the outbreak of the war, the ship was assigned to the 11th Destroyer Flotilla, based out of Plymouth, and in the early stages of hostilities undertook patrols in the English Channel and South Western Approaches areas.

[41] On 29 April 1940, she deployed with the destroyers HMS Echo, Firedrake, Havelock and Arrow to evacuate troops from Mo and Bodø to Harstad.

[14] On the night of 15/16 March, the German submarine U-110, commanded by Fritz-Julius Lemp, sighted the convoy, and made a surface attack, torpedoing the tanker Erdona, which did not sink.

Together, the three destroyers attacked U-110 with depth charges, and Vanoc and Scimitar were assigned to keeping the submarine submerged while the convoy sailed away.

[45] At about 10:00 pm on the night of 16/17 March U-99 under the command of Otto Kretschmer infiltrated the convoy and fired U-99's remaining eight torpedoes, hitting six merchant ships and sinking five of them.

Vanoc spotted the surfaced U-99, and both destroyers opened fire on the stricken U-boat, which was scuttled by her crew as they abandoned ship.

[46][47] From March 1942 she joined the Escort Group B-5 team of destroyers HMS Havelock, Caldwell, Walker, frigate Swale, and corvettes Pimpernel, Godetia, Saxifrage, Buttercup and Lavender.

[48] On 16 March 1944, in the Straits of Gibraltar at position 35°55′N 05°41′W / 35.917°N 5.683°W / 35.917; -5.683 she co-operated with the frigate HMS Affleck and three 3 US Catalina aircraft (VP 63) to sink the submarine U-392 with a hedgehog attack, resulting in 52 dead (all hands) from U-392.