"Princess Royal" provided support for British light forces involved in the Second Battle of Heligoland Bight on 17 November 1917, but never came within range of any German ships. She sailed with the 1st BCS on 12 December after German destroyers sank seven ships of a Norway-bound convoy, including the escorting destroyer , four naval trawlers and four cargo ships earlier that day, but the British were unable to intercept and returned to base the following day. "Princess Royal", along with the rest of the Grand Fleet, sortied on the afternoon of 23 April 1918 after radio transmissions revealed that the High Seas Fleet was at sea after a failed attempt to intercept the regular British convoy to Norway. However, the Germans were too far ahead of the British, and no shots were fired. Starting in July, the Grand Fleet was affected by the 1918 flu pandemic; at one point, "Princess Royal" lacked sufficient healthy crewmen to sail.