Motoscafo armato silurante, alternatively Motoscafo antisommergibili and commonly abbreviated as MAS, was a class of fast torpedo-armed vessels used by the Regia Marina during World War I and World War II. Originally, "MAS" referred to motobarca armata SVAN, Società Veneziana Automobili Navali.
The Italian submarine Acciaio was the name ship of her class of submarines built for the Royal Italian Navy during World War II.
The Italian submarine Flutto was the name ship of her class of submarines built for the Royal Italian Navy during World War II. She obtained no successes during her short career, and was sunk by British ships during the Invasion of Sicily in 1943.
The Argo-class was a class of two coastal submarines built by Cantieri Riuniti dell'Adriatico in Monfalcone for Portugal but operated by the Royal Italian Navy after Portugal was unable to pay construction costs. The submarines were built in 1936, and both served in the Mediterranean Sea at the start of the Second World War. The boats were transferred to the BETASOM Atlantic submarine base at Bordeaux in 1940, but returned to the Mediterranean in 1941, where both were sunk within a few days of the September 1943 Italian armistice.
Giuseppe Finzi was one of three Calvi-class submarines built for the Regia Marina during the 1930s. Completed in 1936, she played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists. The submarine made multiple patrols in the Atlantic Ocean during the Second World War, sinking five Allied ships. Gisueppe Finzi began conversion into a transport submarine in 1943, but was captured by the Germans in September 1943 before it was completed and redesignated as UIT-21. She was scuttled by them in August 1944 to prevent her capture.
Pietro Calvi was the lead ship of its class of two submarines built for the Regia Marina during the 1930s. Completed in 1936, she played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists. The submarine made multiple patrols in the Atlantic Ocean during the Second World War, sinking seven Allied ships. Pietro Calvi was rammed and sunk by a British convoy escort in July 1942.
The Orjen class were motor torpedo boats (MTBs) built for the Royal Navy of Yugoslavia in 1936 and 1937. A total of eight boats were built by the at the Lürssen Shipyard at Vegesack, Germany. They were based on the German S-2 MTBs, and their primary armament was 533 mm (21 in) torpedoes launched from two 550 mm (21.7 in) torpedo tubes, with anti-aircraft protection provided by a 40 mm (1.6 in) gun and a 15 mm (0.59 in) machine gun. At the start of the April 1941 Axis invasion of Yugoslavia, two boats managed to escape to Alexandria in Egypt where they served under the operational command of the British Mediterranean Fleet and under the administrative control of the Yugoslav government-in-exile. Their duties included convoy escort duties and operations against Vichy French forces in Syria. The remaining six boats were captured by Italian forces and commissioned in the Regia Marina with modified anti-aircraft armament, and were heavily employed in the Aegean Sea. They were also used by the Italians as the model for the Italian-built CRDA 60 t motor torpedo boats and the submarine chasers of the VAS class.
The Motosilurante CRDA 60 t was a type of motor torpedo boat built for the Regia Marina during World War II. It was designed on the pattern of German S-boats — some early examples of which were captured by the Italians from Yugoslav Navy — to complement the faster but less seaworthy MAS boats.
Domenico Millelire was one of four Balilla-class submarines built for the Regia Marina during the late 1920s.
Balilla was the lead ship of her class of four submarines built for the Regia Marina during the late 1920s.
Antonio Sciesa was one of four Balilla-class submarines built for the Regia Marina during the late 1920s. She played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists.
Argo was the lead ship of her class of two submarines ordered by the Portuguese government, but taken over and completed for the Regia Marina during the 1930s.
Velella was one of a pair of submarines ordered by the Portuguese government, but taken over and completed for the Regia Marina during the 1930s.
Galatea was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s. She played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists.
Sirena was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s.
Fratelli Bandiera was the lead ship of her class of four submarines built for the Regia Marina during the late 1920s.
Luciano Manara was one of four Bandiera-class submarines built for the Regia Marina during the late 1920s. Completed in 1929,
Giovanni Da Procida was one of four Mameli-class submarines built for the Regia Marina during the 1920s. She played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists.
The Italian torpedo boat Sagittario was a Spica-class torpedo boat built for the Regia Marina in 1936. During the Battle of the Mediterranean, in the Second World War, Sagittario was involved in several convoy missions, the most notable that known as the "Sagittario convoy", in the course of the Battle of Crete, for which her commander, Giuseppe Cigala Fulgosi, was awarded the Gold Medal of Military Valour. Sagittario survived the war. Re-classified as corvette in 1949, she was scrapped in 1964.
The Quarta Flottiglia MAS was an Italian flotilla of the Regia Marina created during the Fascist regime.
