Specifically the 250-350 men of the Operational Raiders Group are the special forces section of the elite unit.
The name referred to an early vehicle employed by the units, an explosive-laden crewless motorboat ("barchino") which was aimed and launched against enemy submersibles (keep in mind that until well after World War II subs were essentially surface ships with the capability of temporarily diving underwater for attacks).
After World War I much study and development went into underwater raid techniques but the unit's name was never altered, leading to the false impression that Italian seafaring commandos were still relegated to anti-submarine warfare only.
Instead many flotillas were armed and equipped to direct raids on enemy ships using explosive head-charges in guided torpedoes with 2-man crews (Siluri a Lenta Corsa or S.L.C.
), with hand explosive charges (by frogmen) or with small, fast, self-explosive boats (S.M.A.).