The story of Italy’s Decima MAS (Decima Mezzi d’Assalto, or 10th Assault Vehicle Flotilla), is a peculiar tale regarding Axis Special Forces in World War II. On one hand they were the best combat frogmen produced by any nation during the conflict. On the other, the courage and innovation they brought to the history of naval warfare became stained by an evil ideology that drove many of them to commit atrocities, not at sea, but on land, after Italy toppled Mussolini and the unit split apart upon deciding where their allegiances lay. This article will focus on how the unit originated, its most storied missions, and how ‘X MAS,’ as it was nicknamed, ultimately met a silent end.

Seeds of this unit began with Italian spearfishing in the Mediterranean in the 1920s and 30s. During this time, the sport evolved from free diving to snorkeling to using rebreathers, which introduced scuba diving to the area and garnered the interest of the Italian navy (Regina Marina). The Italians created their first Special Forces frogman unit, known as the 1st Assault Vehicle Flotilla, around the new equipment in 1939.

Utilizing the ideas of two naval combat engineers, Majors Elios Toschi and Teseo Tesei, the Flotilla, under Commander Paolo Aloisi, began creating tactics based around not only scuba gear, but motor boats and a vehicle unique to the Italian navy, one that was fated to be copied in one form or another all the way down to the present day Swimmer Delivery Vehicle (SDV): The manned torpedo. This versatile two-man craft, known affectionately as ‘Maiale’ (pig), was destined to play a key role in the majority of successes enjoyed by the frogmen.

After Mussolini declared war against Great Britain, Italy joined Germany’s side on June 10, 1940. The next few months saw Italian forces trying to match, without much success, the prowess of their ally, and this included X MAS, which found all of its missions starting from an August 22 attempt against the harbor in Alexandria, Egypt to an October 21st attempt at Gibraltar, ending in failure or cancellation. The closest they got to sinking a ship was when a single Maiali brought its crew under the battleship HMS Barham. Charges were placed but caused little damage. Despite this, lessons were learned from every failure and, when 1941 arrived, X MAS was ready to shine among the rest of Italy’s bumbling military.

Now under its second commanding officer, Commander Vittorio Moccagatta, the unit was divided into two different sections: a surface group operating explosive motor boats, or ‘MTMs,’ and a sub-surface group consisting of Maiali crews and ‘Gamma’ combat swimmers.

The Italian Manned Torpedo

The New Year started off well for X MAS when on March 25, two destroyers departed the Aegean island of Leros carrying 6 MTMs bound for Souda Bay, Crete. Packed into the bow of each one was were 660lbs of explosive, more than enough to cripple or sink even an aircraft carrier with the right hit. The concept behind their use was simple: The pilot aimed it at a ship, pushed the throttle forward then stepped off the back while still a safe distance from detonation.

After dark, at 2330 hours some 10 miles outside the harbor, the six boats under command of Lieutenant Luigi Faggioni departed, and slowly made their way past defenses to pick out four targets: the heavy cruiser HMS York, two tankers and a cargo ship. At 0445 hours the boats gunned their engines and maneuvered for hits amidships. Once the courses were true the pilots splashed into the water, hearing their mounts rapidly grow faint. Then, seconds later, huge spouts of water and flame shot skyward as bows crashed against hulls.