 A major mutiny among crews of the armored cruisers stationed in Cattaro , including <unk> Georg and Kaiser Karl VI , began on 1 February 1918 . Two days later , Erzherzog Ferdinand Max and her sisters arrived in the port and assisted with the suppression of the mutiny . Following the restoration of order in the naval base , the armored cruisers <unk> Georg and Kaiser Karl VI were decommissioned and Erzherzog Ferdinand Max and her sisters were stationed in Cattaro in their place . On the morning of 11 June , Admiral <unk> Horthy planned a major assault on the Otranto <unk> ; the three Erzherzog <unk> and the four Tegetthoff @-@ class battleships were to provide support for the <unk> @-@ class cruisers on an assault on the Allied defenses at the Strait of Otranto . The plan was intended to replicate the success of the raid conducted one year earlier . Horthy 's plan was to destroy the blockading fleet by <unk> Allied ships to the cruisers and lighter ships , which were protected from the heavier guns of the battleships , including the guns of the Erzherzog Karl class . However , on the morning of 10 June , the dreadnought Szent István was torpedoed and sunk by an Italian torpedo boat . Horthy felt that the element of surprise had been compromised , and therefore called off the operation . This was to be the last military action Erzherzog Ferdinand Max was to take part in , and she and her sisters spent the rest of their career in port . 
