The Italian Nautilus was designed by Curio Bernardis, later a well-known submarine designer. Nereides hull, like that of her sister ship, was shaped similar to a torpedo boat. She was 134inchesft4inchesin (ftin) long with a beam of 14inchesft1inchesin (ftin) and a draft of 9inchesft4inchesin (ftin). She was outfitted with two shafts powered by twin 300bhp Sulzer diesel engines for surface running at up to 13.2knots, and twin 160hp Ansaldo electric motors for a maximum of 8knots when submerged. Nereide was armed with two 17.7-1NaN-1 bow torpedo tubes and could carry up to 4 torpedoes. She was designed for a complement of 19–2 officers and 17 sailors.
Nereide was laid down at the Venice Navy Yard on 1 August 1911, and was launched on 12 July 1913. It is not known when Nereide was commissioned, but it was most likely after her completion on 20 December 1913. Little is known about Nereides service career in the Règia Marina before August 1915.
After Italy's entry into World War I, the country's armed forces occupied the island of Pelagosa in the central Adriatic.[1] After scouting reports from the German submarine and from an Austro-Hungarian reconnaissance aircraft reported a French or Italian submarine—which was, in fact, Nereide—at Pelagosa in early August 1915, the Austro-Hungarian Navy dispatched its submarine, under the command of Georg Ritter von Trapp,[2] from nearby Lissa.[3] On the morning of 5 August, Nereide was on the surface, moored under a cliff in the island's harbor.
When U-5 surfaced just offshore, Nereides commanding officer, Capitano di Corvetta Carlo del Greco, cast off the lines and maneuvered to get a shot at von Trapp's boat. Nereide launched a torpedo at U-5 but missed, after which del Greco ordered his boat down. U-5 lined up a shot and launched a single torpedo at the slowly submerging target, striking her, and sending her to the bottom with all hands.[4] [5] Carlo del Greco received the Medaglia d'Oro al Valore Militare for his actions.[6] Nereides wreck was located in 1972 at position 42.3833°N 32°W.[7]