MAS (ships)

Motoscafo armato silurante (Italian: "torpedo armed motorboat"), commonly abbreviated as MAS was a class of fast torpedo armed vessel used by the Regia Marina (the Royal Navy of Italy) during World War I and World War II. Originally, "MAS" referred to motobarca armata SVAN ("armed motorboat SVAN"), where SVAN stood for Società Veneziana Automobili Navali ("Naval Automobile Society of Venice).

MAS were essentially motorboats with displacements of 20–30 tonnes (depending on the class), a 10-man crew, and armament composed of two torpedoes, machine guns and occasionally a light gun.

The term "MAS" is an acronym for Mezzi d'Assalto, ("assault vehicles") in the unit name Flottiglia MAS ("assault vehicles flotilla"), the most famous of which was the Decima MAS of World War II.

MAS were widely employed by Regia Marina during World War I in 1915–1918. Models used were directly derived from compact civilian motorboats, provided with petrol engines which were compact and reliable (characteristics which were not common at the time) . They were used not only in the anti-submarine patrol role, but also for daring attacks against major units of the Austro-Hungarian Navy.

A significant success came in December 1917, when an MAS boat managed to sink the pre-dreadnought battleship SMS Wien in Trieste harbor. The greatest success of Italian MAS was the sinking of the Austro-Hungarian battleship SMS Szent István off Pula on 10 June 1918 by a boat commanded by Luigi Rizzo. MAS boats later engaged in the Second Battle of Durazzo in October 1918.

The main Austrian fleet remained securely at anchor in the harbour at Pola (present-day Pula in Croatia), protected by several layers of defensive booms, impassable to conventional MAS boats. A special version was therefore designed, the Grillo-class tracked torpedo motorboat or Barchino Saltatore ("Jumping Boats"), which featured a pair of spiked continuous tracks, intended to allow them to clamber over the booms which were supported by large timber baulks. The boats were powered by an electric motor for a silent approach and carried two torpedoes. Four were built; the first two were scuttled when their slow motors failed to get them to the harbour booms at Pola before daybreak and in a second operation, another boat made such a loud clattering noise climbing the booms that it was spotted and destroyed by gunfire.

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