'DHU' was a British naval surface force support for the 'DH' carrierborne air attack on shipping in the port of Tromsų in German-occupied Norway (15/19 October 1940).
At 15.50 on 15 October the battle-cruiser Hood departed Scapa Flow in the Orkney islands group escorted by the destroyers Eskimo, Mashona and Somali to provide cover for a force comprising the elderly fleet carrier Furious, the heavy cruisers Berwick and Norfolk, and the destroyers Matabele and Punjabi.
A force of 11 Fairey Swordfish and three Blackburn Skua aircraft from Furious delivered their attack at 04.10 on 16 October, achieving only modest results against the port’s oil tanks and the seaplane base, and Hood's covering force found no employment. This covering force had been despatched following reports of German activity in the Skagerrak which was thought might be German heavy units reacting to Furious's presence.
The British forces returned safely to Scapa Flow early in the afternoon of 19 October.