[3][4] She was propelled by three Yarrow type 250 pound per square inch water tube boilers, powering Brown-Curtis geared independent oil fuelled steam turbines developing 27,120 SHP and driving two screws at 260 RPM for a maximum designed speed of 34 knots.

[1] At the outbreak of WWII in September 1939 Wanderer was sent to Plymouth Navy Base to join the Western Approaches Command along with her flotilla (Vanity, Vansittart, Volunteer, Whitehall, Witch, Witherington and Wolverine), then on the 13th she was sent with HMS Whirlwind to escort convoy OB4 on its initial outward journey.

Convoy duties continued until 27 April 1940 when she was transferred to the Home Fleet to support the evacuation of Allied troops from Norway in Operation Alphabet.

On 29 April along with five other destroyers (Somali, Mashona, Sikh, Walker and Westcott) and the light cruisers Sheffield, Arethusa and Galatea she took passage to Åndalsnes.

[2] Whilst escorting to convoy OB 239 on 2 June 1941 along with the corvette HMS Periwinkle she attacked and sank the first of her five confirmed U-boat kills, U-147 to the west of Skerryvore at 56°38′N 10°24′W / 56.633°N 10.400°W / 56.633; -10.400.

[1] On the evening of 18 August Wanderer was signalled by the C-in-C Western Approaches "Proceed OG 71 and carry out sweep astern of convoy for two hours before returning.

[1] January to May 1943 was spent at HMNB Devonport under refit and conversion as a long range escort; the No.1 boiler (and her forward funnel) was removed to provide space for more fuel tanks and crew quarters; two of her main guns (A and Y) were landed and replaced with a Hedgehog ahead-throwing weapon forward and depth charge stowage and launchers aft; the torpedo tubes were replaced with depth charge stowage and a pair of Oerlikon 20 mm cannon amidships, with a further pair in the bridge wings; the 2-pounders were removed; her gunnery director tower and torpedo control were removed from the bridge to be replaced by an ASDICS control cabinet; she was fitted with Type 144 ASDICS (Sonar), Type 271 target indication radar and Type 291 air warning radar; the latest Wireless telegraphy (W/T), Radio transmitter (R/T) and High-frequency direction finding (H/F D/F) equipment was installed; and Carley rafts were fitted throughout.

[8] They lost contact temporarily as the submarine headed underneath the convoy ships but they eventually picked her up again and with corvette HMS Wallflower began Hedgehog and depth charge runs.

On 17 January Wanderer was searching for a German blockade runner along with frigate Glenarm and the corvette Geranium when they detected a weak sonar contact to the south west of Cape Clear which turned out to be a U-boat.

[15] During 22 to 27 February Wanderer accompanied aircraft carrier HMS Chaser on the Russian Convoy JW 57 which was attacked by U-boats with the loss of one destroyer.

[1][16] Further modifications came in late March as she was fitted rather mysteriously with a single mounted 2 pounder gun on the Forecastle and another Oerlikon 20 mm cannon on the Quarterdeck.

[1][19] On 5 July whilst escorting a convoy north off Pointe de Barfleur Wanderer detected U-390 and along with HMS Tavy began a Hedgehog attack which would lead to her fifth and final U-boat kill at 49°52′N 00°48′W / 49.867°N 0.800°W / 49.867; -0.800.

[21] Whinney was then reassigned and his First Lieutenant was given command to sail Wanderer to Chatham Dockyard for assessment where it was confirmed that the twenty-five-year-old vessel was no longer seaworthy or even repairable.