the new commander of the Austrian fleet, Konteradmiral Miklós Horthy, decided to conduct another attack on the Otranto Barrage to allow more German and Austro-Hungarian U-boats to safely get through the heavily defended strait. During the night of 8 June, Horthy left the naval base of Pola with Viribus Unitis and Prinz Eugen. The other two dreadnoughts, and Tegetthoff, 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. 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 failed. MAS 15 managed to hit Szent István with her torpedoes at about 3:25 am. Both boats were then chased away from the scene by the Austrian escort vessels. Despite attempts to take the crippled Szent István into tow by Tegetthoff, the ship continued to sink and the attempt was abandoned. A few minutes after 6:00 am Szent István sank. Admiral Horthy, commander of the proposed attack, soon canceled the attack because he thought that the Italians had discovered his plan and ordered the ships to return to Pola. On the contrary, the Italians did not even discover that the Austrian dreadnoughts had departed Pola until later on 10 June when aerial reconnaissance photos revealed that they were no longer there. This was the last military operation that the Viribus Unitis was to take part in and she spent the rest of her career at port in Pola. Italian attack and sinking By October 1918 it had become clear that Austria-Hungary was facing defeat in the war. The Austrian government decided to give Viribus Unitis, along with much of the fleet, to the newly formed State of Slovenes, Croats and Serbs. This was considered preferential to handing the fleet to the Allies, as the new state had declared its neutrality. The transfer to the State of Slovenes, Croats and Serbs took place in the evening of 31 October, and Viribus Unitis was renamed Jugoslavija. On 1 November 1918, two men of the Italian Navy, Raffaele Paolucci and Raffaele Rossetti, rode a primitive manned torpedo (nicknamed