The torpedoing of the armoured cruiser by the German submarine on effectively confined both "Andrei Pervozvanny"-class ships to harbour for the rest of the war. All battleships were ordered to return to safety of Finnish bases and stay there until the Navy could cope with the submarine threat. "Slava" and "Tsesarevich" returned to action in the Battle of the Gulf of Riga in 1915, but "Imperator Pavel I" remained moored in Helsingfors. "Andrei Pervozvanny" was mobilized for active operations twice, in April and November 1916. The first operation, a raid on a German convoy near the Swedish coast, was a moderate success; the second ended in a humiliating retreat after "Rurik" struck a mine laid by the German submarine UC 27. In October 1916 the crew of "Imperator Pavel I", demoralized by boredom and Bolshevik propaganda, refused to obey orders and demanded better rations and easing of service. The Navy preferred to appease the sailors, and the ringleaders escaped punishment. In late 1916, the ships were fitted with four 3-inch Lender anti-aircraft guns.