Italian submarine Nereide

Nereide was a Nautilus-class submarine in the Italian Royal Navy (Règia Marina) during World War I. She was built 1911–1913 at the navy yard at Venice and was sunk in 1915 by the Austro-Hungarian submarine SMS U-5 (Austria-Hungary) under the command of Georg Ritter von Trapp. Nereide's captain, Carlo del Greco posthumously received the Medaglia d'Oro al Valore Militare for his actions when Nereide was sunk.

Design and construction
The Italian Nautilus-class submarine was designed by Curio Bernardis, later a well-known submarine designer. Nereide's hull, like that of her sister ship ITALIAN SUBMARINE Nautilus, was shaped similar to a torpedo boat. She was 134 ft long with a beam of 14 ft and a draft of 9 ft. She was outfitted with two shafts powered by twin 300 bhp Sulzer diesel engines for surface running at up to 13.2 knots, and twin 160 hp Ansaldo electric motors for a maximum of 8 knots when submerged. Nereide was armed with two 17.7 in 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 Nereide's service career in the Règia Marina before August 1915.

Sinking
After Italy's entry into World War I, the country's armed forces occupied the island of Pelagosa in the central Adriatic. After scouting reports from the German submarine SMS UB-14 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 SMS U-5 (Austria-Hungary), under the command of Georg Ritter von Trapp, from nearby Lissa. 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, Nereide's 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. Carlo del Greco received the Medaglia d'Oro al Valore Militare for his actions.

Nereide's wreck was located in 1972 at position 42.38333°N, 16.26667°W.