Italian submarine Turchese was a built for the Royal Italian Navy (Regia Marina) during the 1930s. She was named after a gemstone Turquoise. Design and description The Perla-class submarines were essentially repeats of the preceding . The modifications that were made compared to the boats of the previous series were mostly of upgrade nature. Among them were enlargement of the false tower at the top, more modern engines, installation of a radiogoniometer that could be controlled from inside the ship. Improvements and the installation of new air conditioning equipment meant a slight increase in displacement, and increase in the fuel stowage also increased the autonomy of these boats compared to the previous series. Their designed full load displacement was surfaced and submerged, but varied somewhat depending on the boat and the builder. The submarines were long, had a beam of and a draft of to . For surface running, the boats were powered by two diesel engines, each driving one propeller shaft with overall power of . When submerged each propeller was driven by a electric motor. They could reach on the surface and underwater. On the surface, the Perla class had a range of at , submerged, they had a range of at . The boats were armed with six internal torpedo tubes, four in the bow and two in the stern. One reload torpedo was carried for each tube, for a total of twelve. They were also armed with one deck gun for combat on the surface. The light anti-aircraft armament consisted of one or two pairs of machine guns. Construction and career Turchese was built by CRDA at their shipyard in Monfalcone, laid on 28 September 1935, launched on 19 July 1936, and completed on 21 September 1936. After delivery, Turchese was assigned to the 34th Squadron (III Submarine group) based at Messina. After brief training, she carried out a long endurance cruise in the Dodecanese in the fall of 1936. In 1937 she carried out a training campaign in the Dodecanese and the Mediterranean, followed by another one in 1938. On October 15, 1938, she was temporarily assigned to Flotilla Submarine school. In 1939 Turchese returned to active duty, and formed the 72nd Squadron (VII Submarine Group) based at Cagliari together with , and . Turchese remained assigned to this Squadron until the end of her career. After the outbreak of hostilities Turchese was under command