This was a British naval undertaking within 'Kinetic' for a patrol in the Bay of Biscay to locate and sink German shipping (5/28 August 1944).
The ships involved were the light cruisers Diadem and Mauritius, each accompanied by two destroyers of the 10th Destroyer Flotilla. Diadem was supported by Onslow and the Polish Piorun as Force 28, sank Sperrbrecher 7 off La Rochelle, and with the destroyers shelled German positions on the Ile de Yeu.
Mauritius was deployed in the Bay of Biscay on 5 August to intercept German craft evacuating troops, and on 14 August became the core of Force 27 patrolling off Les Sables with the destroyers Ursa and Canadian Iroquois. The ships engaged a German convoy, damaging the torpedo boat T 24 and two ships she was escorting. The British ships later engaged a German coastal steamer, which grounded. On 15 August the British ships engaged two minesweepers escorting two merchant vessels off the Ile de Yeu and sank one of the minesweepers.
On 22 August Task Force 27 came under shore fire while patrolling off the estuary of the Gironde river, and three days later engaged an escorted convoy in Audierne Bay, sinking the patrol boats V 702, V 717, V 720, V 729 and V 730, and setting the merchant vessels on fire. The 'Assault' patrol ended on 28 August, when the French resistance reported that the Germans were leaving the Brittany area.