Other Xª MAS men in southern Italy or other Allied-occupied areas joined the Italian Co-Belligerent Navy as part of the Mariassalto (Naval Assault) unit.

In World War I, on 1 November 1918, Raffaele Paolucci and Raffaele Rossetti of the Regia Marina rode a human torpedo (nicknamed Mignatta or "leech") into the harbour of Pula, where they sank the battleship Jugoslavija, of the navy of the State of Slovenes, Croats and Serbs, formerly the Austro-Hungarian battleship SMS Viribus Unitis, and the freighter Wien using limpet mines.

[citation needed] In the 1930s Italian sport spearfishermen began using industrial or submarine-escape oxygen rebreathers, starting scuba diving in Italy.

In 1941, Commander Vittorio Moccagatta re-organised the First Flotilla into the Decima Flottiglia MAS, and divided the unit into two parts – a surface group operating fast explosive motor boats, and a sub-surface weapons group using human torpedoes called SLC (siluri a lenta corsa or "slow-running torpedoes", but nicknamed Maiale or "Pig" by their crews), as well as "Gamma" assault swimmers (nuotatori) using limpet mines.

The maiale crews the Gamma frogmen wore Belloni rubberised suits with a closed-circuit re-breathing apparatus to avoid bubbles.

[5] The modified destroyers Francesco Crispi and Quintino Sella, had carried the MTM used in the successful Raid on Souda Bay (25/26 March 1941).

Italian submarine Gondar was sunk on 30 September, even though the three maiali cylinders could be flooded, allowing the boat to reach a depth of 295 ft (90 m).

Early in 1941, a smaller MT Ridotto was built with a height of 3 ft 9 in (1.14 m) to fit inside the deck cylinders of submarines with the same explosive charge but they were never used in this manner.

Some Decima MAS sailors joined the Allied cause to fight against Nazi Germany and what remained of the Axis as part of the Italian Co-Belligerent Navy.

A new unit was formed, led by Forza and joined by some of the pioneers such as de la Penne newly released from British POW camps.

Led by Borghese, Decima Flottiglia was revived, as part of the National Republican Navy (Marina Nazionale Repubblicana) of the RSI with its headquarters in Caserma del Muggiano, La Spezia.

On 18 April 1945 the destroyer Legionario, carrying two high-speed motorboats equipped with chariots sailed from Venice for Genoa led by Captain Chavasse SOE and Forza.

Both chariots were deployed and succeeded in penetrating the defences but found the hull of Aquila so encrusted with barnacles and seaweed the limpet mines could not be attached to it.

Some Xª MAS men who were in German-occupied Italy remained part of the Axis forces, joining the Italian Social Republic under the command of Captain Borghese.

The corps had its own weekly magazine, L'orizzonte ("The Horizon"), in which authors such as Giovanni Preziosi wrote vehemently anti-Semitic articles about Jewish conspiracies.

[24] Quando pareva vinta Roma antica, sorse l'invitta decima legione; vinse sul campo il barbaro nemico, Roma riebbe pace con onore; quando l'ignobil 8 di settembre, abbandonò la patria il traditore, sorse dal mar la decima flottiglia, che prese l'armi al grido "per l'onore!

On 14 January 1944 Benito Mussolini arrested Borghese while receiving him in Gargnano, in order to gain direct control of the Xª MAS.

However, the German command used their influence to have Borghese released, as they needed the equipment, expertise and manpower of the Xª MAS as an anti-partisan force.

[20] In November 1944 four frogmen (Malacarne, Sorgetti, Bertoncin, Pavone), who had stayed under German command, were delivered by fast motorboat and swam into Livorno harbor to set up a secret sabotage base, but were captured.

However, the Xª MAS units also earned a good combat reputation fighting on the frontline against the Allies at Anzio and on the Gothic Line.

In the last months of the war Xª MAS units were dispatched to the eastern Italian border against Josip Broz Tito's partisans who marched into Istria and Venezia Giulia.

He was soon arrested by partisans, but rescued by OSS officer James Angleton, who dressed him in an American uniform and drove him to Rome for interrogation by the Allies.

One of the best scenes features a boisterous and crazy assault diver and parachute Commando frogman called Barbacane (Giuseppe Maffioli).