Calvi - class submarine The " Calvi " - class was a class of three submarine s built by Oderno - Terni - Orlando in Genoa for the Royal Italian Navy ( ) . The submarines were built in 1935 , and all three served in the Mediterranean at the start of the Second World War . The boats were transferred to the BETASOM German submarine base at Bordeaux in August 1940 . In December 1941 the boats were used for a rescue mission of 254 sailors from the sunken German auxiliary cruiser Atlantis . After " Calvi " had been sunk , " Finzi " and " Tazzoli " were selected for conversion to " transport submarine s " in order to exchange rare or irreplaceable trade goods with Japan . Cargo capacity of 160 tons reduced reserve buoyancy from 20 – 25 % to 3 . 5 – 6 % ; and armament was reduced to defensive machine gun s . Ships . " Pietro Calvi " . " Pietro Calvi " ( pennant number CV ) was launched 31 March 1935 . The first war patrol was from Liguria to the Atlantic Ocean , and lasted from 3 July to 6 August 1940 . After overhaul at La Spezia , " Calvi " sailed on 6 October 1940 for a second Atlantic patrol reaching Bordeaux on 23 October . " Calvi " suffered storm damage during its third patrol off the British Isles from 3 to 31 December 1940 . The fourth patrol was between the Canary Islands and the Azores from 31 March to 13 May 1941 . " Calvi " sailed on 1 August 1941 for a fifth patrol off the Canary Islands . During the sixth patrol from 7 to 29 December 1941 " Calvi " , " Finzi " and " Tazzoli " rescued sailors of the sunken raider " Atlantis " . The seventh patrol was off Brazil from 7 March to 29 April 1942 . " Calvi " sailed on 2 July 1942 for its eighth patrol . " Calvi " was rammed and sunk on 14 July 1942 by convoy SL 115 escort HMS " Lulworth " . Three officers and 32 sailors survived . " Giuseppe Finzi " . " Giuseppe Finzi " ( pennant number FZ ) was launched 29 June 1935 . The first war patrol was from Cagliari to the Atlantic , and lasted from 5 June to 10 July 1940 . " Finzi " sailed on 7 September 1940 and passed the Strait of Gibraltar on 13 September for an Atlantic patrol to Bordeaux on 29 September . Admiral Karl Dönitz visited " Finzi " on 30 September to welcome " Regia Marina " sailors to the German base . The third patrol near the British Isles from 24 October to 4 December 1940 revealed that the diesel engine air intake was too exposed for North Atlantic winter weather . The fourth patrol was near the Canary Islands from 10 March to 17 April 1941 and the fifth patrol was off Gibraltar in August . During the sixth patrol from 7 to 29 December 1941 " Calvi " , " Finzi " and " Tazzoli " rescued sailors of the sunken raider " Atlantis " . " Finzi " sailed for Operation Neuland on 6 February 1942 and returned on 31 March . " Finzi " returned to the Caribbean Sea for an eighth patrol from 6 June to 18 August 1942 . On 26 November 1942 " Finzi " sailed for a ninth patrol to Brazil ; but mechanical problems required return to base on 10 December . " Finzi " patrolled the west African coast from 11 February to 18 April 1943 . Conversion to a transport submarine was never completed ; and the boat was scuttled at Le Verdon - sur - Mer on 25 July 1944 . " Enrico Tazzoli " . " Enrico Tazzoli " ( pennant number TZ ) was launched 14 October 1935 . It was named after Enrico Tazzoli , a martyr of the Italian wars of independence . The first wartime patrol was off the coast of north Africa from 21 June 1940 to 2 July . The second was an unsuccessful attempt to pass the Strait of Gibraltar from 30 July to 9 August 1940 . After overhaul at La Spezia , " Tazzoli " sailed on 2 October 1940 and passed the Strait of Gibraltar on 7 October for an Atlantic patrol to Bordeaux on 24 October . The fourth patrol was off the British Isles from 13 December 1940 to 6 January 1941 . " Tazzoli " sailed on 7 April 1941 to patrol between Freetown and the Azores ; and shot down an attacking Bristol Blenheim while returning to port on 23 May . The sixth patrol was again off Freetown from 15 July to 11 September 1941 . During the seventh patrol from 7 to 27 December 1941 " Calvi " , " Finzi " and " Tazzoli " rescued sailors of the sunken raider " Atlantis " . " Tazzoli " sailed for Operation Neuland on 2 February 1942 and returned on 31 March . The ninth patrol was again to the Caribbean from 18 June to 5 September 1942 ; and the tenth patrol was to Brazil from 14 November 1942 to 2 February 1943 . After conversion to a transport submarine , " Tazzoli " sailed for Japan on 16 May 1943 and was sunk by aircraft in the Bay of Biscay on 23 May .