Dunkirk 1940 Vanquisher took part in history's first deployment of operational magnetic bottom mines when she joined Abdiel, Telemachus, and the destroyers Tarpon, Vanoc, and Venturous, escorted by eight other destroyers, in laying 234 Sinker Mk1(M) mines in the North Sea off the coast of Flanders, Belgium, about eight nautical miles (15 km) north of Dunkirk, France, on 8 August 1918. German forces did not interfere with the operations. She also participated with Abdiel, Tarpon, Telemachus, and Venturous in the second operation to lay Sinker mines on 22 August 1918, in the North Sea off Flanders about 17 nautical miles (31 km; 20 mi) north of Zeebrugge, Belgium, supported by Royal Air Force aircraft which patrolled to prevent German aerial observation of the operation.[6] In January 1940, Vanquisher underwent post-repair acceptance trials, then returned to convoy defence operations in the Western Approaches with the 11th Destroyer Flotilla, later being reassigned to the English Channel and Southwestern Approaches. In May 1940 she was again reassigned, this time under the Commander-in-Chief, Dover to take part in Operation Dynamo, the evacuation of Allied troops from Dunkirk, France, which she joined on 28 May 1940. She made seven trips between Dunkirk and Dover, England, carrying 241 troops in a voyage on 29 May 582 and 622 troops in two trips on 30 May, 640 and 168 troops in two voyages on 1 June 1940, and 37 and 414 troops in two trips on 3 June 1940. On 12 June 1940 she joined the escort of the French battleship Jean Bart on Jean Bart's voyage from Saint-Nazaire, France, to Casablanca, French Morocco, then on 19 June 1940 steamed to Saint-Nazaire to take part in Operation Aerial, the evacuation of British Expeditionary Force personnel from French ports on the Bay of Biscay. On 20 June 1940, she embarked a demolition party and steamed to La Pallice to destroy port facilities there, but did not land the team. She returned to the United Kingdom at Plymouth on 22 June 1940.[2] Vanquisher continued her North Atlantic convoy operations into 1944, and escorted Convoy ONS 29 with the rest of the 6th Escort Group during February 1944. In May 1944, she was selected for participation in Operation Neptune, the assault phase of the Allied invasion of Normandy scheduled for early June 1944, and was assigned to Escort Group 106 with the frigate Strule, the corvettes Abelia and Balsam, and motor launches of the Royal Navy Coastal Forces for the operation. In early June, she joined Escort Group 106 at Milford Haven, Wales, and on 4 June the group, supplemented by two more corvettes and the naval trawlers Caldy and Gweal, rendezvoused with an assault convoy, Convoy EMB 3 – consisting of 11 empty motor transport ships – in the Irish Sea. On 5 June, the landings were delayed for 24 hours due to bad weather, but on 6 June, the day of the initial landings, Vanquisher and the other ships of her convoy moved to ports on the south coast of England, where the motor transport ships were loaded. On 7 June, the convoy made its passage to the beachhead, and on 8 June it arrived off the invasion beaches and discharged its cargo. On 10 June, Vanquisher began escorting convoys carrying reinforcements and supplies from Falmouth to the beachhead, continuing in this role until Operation Neptune concluded toward the end of June. She then returned to the 6th Escort Group and escorted North Atlantic convoys for the rest of 1944 and into 1945.[2] Winser, John de D. (1999). B.E.F. Ships Before, At and After Dunkirk. Gravesend, Kent: World Ship Society. ISBN 0-905617-91-6.