Quoted from that site:
6.12.1940
Smg. “Bagnolini” attacks and sinks the english cruiser “HMS Calypso” (first italian success in the conflict).
12.19.1941
Smg. " Scire’ " brings to the port of Alessandria (Egypt), the assault team who heavly damage “HMS Valiant” and “HMS Queen Elizabeth” (heroic action of Adm. Luigi Durand de La Penne).
March 1942
Italian Submarines sink several U.S. merchant (68.000 tonn.) close to U.S coasts.
April 1943
“Smg. Da Vinci” and " Smg. Finzi", for the first time, conduct missions in the Indian Ocean.
Italian Submarines WWII Statistics
Active Boats 172
Missions done 1750
Miles done 2.500.000
Days at sea 24.000
Attacks done 173
Torpedos launched 427
Ships sunk from italian submarines
Merchant Ships 132 (665.317 tonn.)
Military Ships 18 (28.950 tonn.)
Italian Submarines lost
Mediterrean Sea 88
Other Sectors 40