Mischief ???
Please, elaborate...
Italians started scuba diving for military operations during WW2.
The initial group of divers were called Gamma Men, but actually they included also one woman.
They did develop special equiment, such as waterproof suits in rubber, full face masks, fins, and the famous ARO rebreather, which was at the time the most advanced scuba system, derived by improving an English system.
This Gamna Group did include Luigi Ferraro, probably the most successfull military diver of all times, as he alone did sink at least 4 English vessels. His wife was the only woman in the team, although she was never deployed in active military actions.
They also used SLCs, also called "maiali" (pigs), slow propeller-driven torpedoes. Using them, a group of Gamma incursors, called X MAS, did sink the English ships HMS Queen Elizabeth and HMS Valiant inside the port of Alexandria.
After the end of WW2, Luigi Ferraro was the very first instructor organising sport scuba diving courses, back in 1948.
He and his friend (and business partner) Jacques Cousteau later founded the CMAS.
I see no "mischief" in all of this...