 By mid 1918 , the new commander of the Austrian fleet , Konteradmiral Miklós Horthy decided to conduct another attack on the Otranto Barrage , similar to the Otranto Raid from December 1916 , to allow more German and Austro @-@ Hungarian U @-@ boats to safely get through the heavily defended strait of Otranto . During the night of 8 June , Horthy left the naval base of Pola with Viribus Unitis and Prinz Eugen . Tegetthoff and her sister ship SMS Szent István , along with one destroyer and six torpedo boats departed Pola on 9 June . At about 3 : 15 on the morning of 10 June , two Italian MAS boats , MAS 15 and MAS 21 , spotted the Austrian fleet steaming south . The MAS platoon was commanded by Capitano di fregata Luigi Rizzo while the individual boats were commanded by Capo timoniere Armando Gori and Guardiamarina di complemento Giuseppe Aonzo respectively . Both boats successfully penetrated the escort screen and split to engage each of the dreadnoughts . MAS 21 attacked Tegetthoff , but her torpedoes missed the battleship . Despite missing Tegetthoff , the other boat , MAS 15 , managed to hit Tegetthoff 's sister ship Szent István with her torpedoes at about 3 : 25 am . Both boats were then chased away from the scene by Austrian escort vessels . Immediately following the attack , Tegetthoff thought that the torpedoes were fired by submarines instead of MAS boats and pulled out of the formation of battleships and destroyers and began to zigzag to throw off any more possible submarine attacks . She continually fired on suspected submarine periscopes until she rejoined Szent István at 4 : 45 . 
