 In February 1917 , Revenge replaced Marlborough as the 1st Battle Squadron flagship ; she thereafter served as the second command flagship . She was briefly replaced in this role by Emperor of India in May and she temporarily became a private ship . Toward the end of the year , the Germans began using destroyers and light cruisers to raid the British convoys to Norway ; this forced the British to deploy capital ships to protect the convoys . On 23 April 1918 , the German fleet sortied in an attempt to catch one of the isolated British squadrons , though the convoy had already passed safely . The Grand Fleet sortied too late the following day to catch the retreating Germans , though the battlecruiser SMS Moltke was torpedoed and badly damaged by the submarine HMS <unk> . In 1918 , Marlborough and her sisters received flying @-@ off platforms on their " B " and " Q " turrets to handle reconnaissance aircraft . 
