On December 12th Submarines D 7 and D 8, which were based temporarily on Blyth, were directed to leave for the Norwegian coast to operate against enemy trade and against enemy submarines. D 7 was directed to make the Ryvingen Light during the dark hours and then to cruise to intercept trade between Ryvingen and Arendal, and between Ryvingen and the west coast of Denmark. It was anticipated that this might draw enemy submarines to the northward from German ports to try to sink D 7, and D 7 was directed to be back at Ryvingen 36 hours after she expected that the first vessel she examined had reached port, so that she might be ready to attack enemy submarines sent after her. D 8 was directed to cruise on a bearing 270° from the Hantsholm Light (coast of Denmark) in order to intercept enemy submarines sent after D 7. Bad weather prevented D 7 leaving before December 15th. The enemy was apparently not drawn, and no success was obtained. On December 15th the 2nd Cruiser Squadron left Scapa for a sweep to the south-eastward, and returned on the 17th. Two neutral ships, steaming at high speed at night without lights on the 15th and 16th, evidently intending to evade the blockade, were intercepted by the 10th Cruiser squadron and sent into Kirkwall. On December 20th Commodore Tyrwhitt left Harwich with the 5th Light Cruiser Squadron, to sweep to the Danish coast, and the Battle Cruiser Fleet was kept at the usual short notice for steam during the time that he was absent until the 23rd. On December 24th the 1st Cruiser Squadron left Scapa to search the central portion of the North Sea. During the day anxiety was felt as to the safety of the destroyers _Porpoise_ and _Morning Star_, which had been escorting a Russian ice-breaker to the northward and which had hove to near the Fair Island Channel in a heavy gale during the 23rd. The 1st Cruiser Squadron was directed to spread and search for them, and the _Hampshire_ and _Donegal_ were also sent from Scapa to endeavour to gain touch. Both the destroyers, however, reached Cromarty in safety, the _Porpoise_ on the 25th, and the _Morning Star_ on the 26th, after having experienced very heavy weather. Many compartments were flooded, and very considerable damage was done. They had been handled with great ability during the exceptionally heavy weather. The 1st Cruiser Squadron, with the _Hampshire_ and _Donegal_, returned to Scapa on the 26th. On the 24th the 3rd Light Cruiser Squadron also proceeded from Rosyth to search the North Sea, down to the vicinity of the Dogger Bank, thence towards the Little Fisher Bank, and back to Rosyth. No enemy vessels were sighted. The weather in the North Sea at this period was very severe, and the _Sappho_, which was supporting the armed trawler patrol to the north-eastward of Peterhead, lost her rudder in a heavy sea.