Italian submarine Diaspro was a built for the Royal Italian Navy (Regia Marina) during the 1930s. She was named after a gemstone Jasper. 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 Diaspro was built by CRDA at their shipyard in Trieste, laid on 29 September 1935, launched on 5 July 1936 and completed on 22 August 1936. After delivery, Diaspro was assigned to the 35th Squadron (III Submarine Group) based at Messina. After a brief training, she carried out a long endurance cruise in the Mediterranean. During the Spanish Civil War she carried out two special missions under command of captain Giuseppe Mellina. During the first one, Diaspro sailed from Trapani on August 5, 1937, heading to patrol an area north of Cape Bon. During her patrol in the Strait of Sicily along the African coast, Diaspro attempted 25 attack attempts, and on August 13, 1937, launched torpedoes against two ships, one of them probably being the French cargo ship , but missed both times. Diaspro