Diana was a fast aviso (Italian: avviso veloce) or sloop of the Italian Italian: [[Regia Marina]] which served during the Second World War. Originally designed as a yacht and despatch vessel for the Italian Head of Government, she was converted for military use.
Diana was laid down on 31 May 1939 at the Cantieri Navali del Quarnaro in Fiume, launched on 20 May 1940 and completed on 12 November 1940. The planned main armament consisted of two 90/50 guns, modern anti-aircraft weapons used on the latest Italian battleships but eventually a pair of old 102/35 4-inch guns was fitted in their place. Six 20 mm Breda 20/65 mod. 35 guns completed the anti-aircraft defence. During the war Diana was used as fast transport for valuable cargo.
The ship left Messina, Italy on 28 June 1942 to bring material and personnel to Tobruk, a city recently reconquered by the Axis forces.In what he described as his "most satisfactory patrol" in the Mediterranean, in June 1942, Sir Hugh Mackenzie, Commander of the British submarine, reported that on their way back to Alexandria, north of Tobruk, they received a signal about an Axis ship which was due in the area at 12 O'clock on the following day and that it was vitally important to sink it (presumed to be Diana). The ship wasn't sighted the following day, but during the night, they received another signal about the same ship going to be in a certain position at 12 O'clock on the following day, and; that it was vitally important to sink the ship. The ship was carrying petrol for an Axis offensive.
On 29 June 1942, about north of the Gulf of Bomba, north-west of Tobruk, Diana detected the launch of four torpedoes. Thrasher had fired the torpedoes, two of which were avoided with a quick turn but the other two exploded aft causing Diana to sink in less than 15 minutes at 33° 30'N and 23° 30' E.[1] Some of the escort boats, after having failed to sink Thrasher, rescued survivors. Later, between 29 and 30 June, the hospital ship Arno arrived, which took care, albeit in rough seas, of the recovery of the 119 survivors; 336 members of the crew had been killed.[2]