 This weapon was called "mignatta" (leech) and was the precursor of the maiale of World War II and the actual "human torpedo".On 1 November 1918 Rossetti used his "mignatta" to assault with Raffaele Paolucci the formerly Austrian battleship "Viribus Unitis", which, unknown to them (the transfer had taken places a few hours before the action, when Luigi Rizzo had already left his base) had already changed hands to the newly established State of Slovenes, Croats and Serbs and renamed "Jugoslavija".After entering Pola harbour undetected, Rossetti and Paolucci placed limpet mines below the hull of the battleship; they were discovered and captured, and they informed the crew that the ship was going to sink, although they did not reveal that they had placed mines on the hull.