Ships in class: 4
The Balilla-class were cruiser submarines built early in the interwar period. They were intended originally to patrol the Indian Ocean and protect Italian interests there, but upon Italy's declaration of war they were stationed in the Mediterranean. The vessels were too large to make good patrol vessels within the Mediterranean and were instead used to ferry supplies to North Africa. The boats were armed with four tubes fore and two aft, and they carried two reloads for the fore tubes and a single reload for those aft. They also bore a 120mm deck gun and a pair of 13.2mm machine guns. The single successful engagement for the class involved the sinking of the British submarine HMS Triad by Enrico Toti. Three of the four would survive the war, with the remaining scuttled after taking heavy damage.