Italian submarine Otaria (1935)

Otraria was one of two Argo-class submarines ordered by the Portuguese government, but taken over and completed for the Regia Marina (Royal Italian Navy) during the 1930s. She played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists.

Design and description
The Glauco-class submarines were improved versions of the preceding Squalo-class submarine. They displaced 1054 LT surfaced and 1305 LT submerged. The submarines were 73 m long, had a beam of 7.2 m and a draft of 5.12 m. They had an operational diving depth of 90 m. Their crew numbered 58 officers and enlisted men.

For surface running, the boats were powered by two 1500 bhp diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 600 hp electric motor. They could reach 17 kn on the surface and 8 kn underwater. On the surface, the Glauco class had a range of 9760 nmi at 8 kn; submerged, they had a range of 110 nmi at 3 kn.

The boats were armed with eight internal 53.3 cm torpedo tubes, four each in the bow and stern for which they carried a total of 14 torpedoes. They were also armed with two 100 mm deck guns, one each fore and aft of the conning tower, for combat on the surface. Their anti-aircraft armament consisted of one or two 13.2 mm machine guns.

Construction and career
Otraria was laid down by CRDA in its Trieste shipyard. The submarine had initially been ordered in 1931, but was acquired by the Italians when Portugal cancelled the order. She was launched on 20 March 1935 and entered service in January 1936. During the Spanish Civil War she attempted to torpedo a Republican destroyer in Cartagena, but missed with the torpedo detonating against a mole. Otraria survived the Second World War and was discarded on 1 February 1948.