The Grand Fleet sortied on 18 August to ambush the High Seas Fleet while it advanced into the southern North Sea, but a series of miscommunications and mistakes prevented Jellicoe from intercepting the German fleet before it returned to port. Two light cruisers were sunk by German U-boats during the operation, prompting Jellicoe to decide to not risk the major units of the fleet south of 55° 30' North due to the prevalence of German submarines and mines. The Admiralty concurred and stipulated that the Grand Fleet would not sortie unless the German fleet was attempting an invasion of Britain or there was a strong possibility it could be forced into an engagement under suitable conditions. "Superb" was refitting at this time and did not participate in this action. On 2 January 1918, Hyde Parker was relieved by Captain Sidney Drury-Lowe before he was transferred to command the battleship on 3 April. The ship began a refit that same month before recommissioning in June. Captain Stephen Radcliffe assumed command of the ship on 22 June and remained in command until 15 December 1919.