 In 1918 Admiral Miklós Horthy de Nagybánya became rear admiral of the fleet , and he determined to use the fleet to attack the Otranto Barrage . On 8 June 1918 he took Viribus Unitis and Prinz Eugen south with a small supporting flotilla ; on the evening of 9 June , Szent István and Tegetthoff followed . In trying to make maximum speed in order to catch up , Szent István 's turbines started to overheat and speed had to be reduced to 12 knots ( 22 km / h ; 14 mph ) . When an attempt was made to raise more steam in order to increase to 16 knots ( 30 km / h ; 18 mph ) Szent István produced an excess of smoke , attracting the attention of a pair of patrolling Italian torpedo boats at 3 @.@ 20 a.m. on 10 June . MAS @-@ 21 attacked Tegetthoff , but one of her torpedoes failed to leave the launch tube and the other failed to explode . MAS @-@ 15 however succeeded in striking Szent István with two torpedoes at 3 : 31 a.m. Tegetthoff returned to the scene to take Szent István in tow . An attempt to beach the ship on nearby Molat Island ( northwest of Zara ) was considered , but the ship was taking on too much water . At 6 : 12 am , with the pumps unequal to the task , Szent István capsized , taking 89 of her crew with her . The last half @-@ hour of the sinking was filmed in stages from Tegetthoff ( one of only two battleship sinkings on the high seas to ever be filmed , the other being that of the British battleship HMS Barham in the Second World War ) . Fearing further attacks by torpedo boats or destroyers from the Italian navy , his element of surprise now compromised , Admiral Horthy called off the attack and the fleet returned to base for the remainder of the war . 
