North Sea on 26 February 1916; Jellicoe had intended to use the Harwich Force to sweep the Heligoland Bight but bad weather prevented operations in the southern North Sea, and the operation was confined to the northern end. Another sweep began on 6 March but was abandoned the following day as the weather grew too severe for the destroyer escorts. On the night of 25 March, Erin and the rest of the fleet sailed from Scapa Flow to support Beatty's battlecruisers and other light forces raiding the German Zeppelin base at Tondern. By the time the Grand Fleet approached the area on 26 March, the British and German forces had already disengaged and a strong gale threatened the light craft, so the fleet was ordered to return to base. On 21 April, the Grand Fleet conducted a demonstration off Horns Reef to distract the Germans while the Russian Navy re-laid its defensive minefields in the Baltic Sea. The fleet returned to Scapa Flow on 24 April and refuelled before sailing south, over intelligence reports that the Germans were about to launch a raid on Lowestoft, but the Germans had withdrawn before the fleet arrived. On 2–4 May, the Grand Fleet conducted another demonstration off Horns Reef to keep German attention on the North Sea. Battle of Jutland To lure out and destroy a portion of the Grand Fleet, the High Seas Fleet (Admiral Reinhard Scheer) composed of 16 dreadnoughts, 6 pre-dreadnoughts and supporting ships, departed the Jade Bight early on the morning of 31 May. The fleet sailed in concert with Rear Admiral Franz von Hipper's five battlecruisers. Room 40 at the Admiralty had intercepted and decrypted German radio traffic containing plans of the operation. The Admiralty ordered the Grand Fleet, with 28 dreadnoughts and 9 battlecruisers, to sortie the night before, to cut off and destroy the High Seas Fleet. During the Battle of Jutland on 31 May, Beatty's battlecruisers managed to bait Scheer and Hipper into a pursuit as they fell back upon the main body of the Grand Fleet. After Jellicoe deployed his ships into line of battle, Erin was the fourth from the head of the line. Scheer's manoeuvres after spotting the Grand Fleet were generally away from Jellicoe's leading ships, and the poor visibility hindered their ability to close with the Germans before Scheer could disengage under the cover of darkness. Opportunities to shoot during