After Provana's 1940 sinking, the remaining boats were transferred to the BETASOM Atlantic submarine base at Bordeaux in August 1940.

After four boats had been sunk in the Atlantic, Barbarigo and Comandante Cappellini were then selected for conversion to "transport submarines" in order to exchange rare or irreplaceable trade goods with Japan.

[6] j According to the Daily Telegraph obituary of Cpt Humphrey Boyes-Smith RN who died 24/6/99, Nani was sunk by depth charges from the Flower-class corvette HMS Anemone on 7/1/41.

After sinking two ships in six BETASOM patrols, Veniero sailed from Bordeaux on 8 August 1941 and returned through the Strait of Gibraltar to La Spezia on 2 September.

On its seventh patrol after return to the Mediterranean, Veniero was assumed sunk (identification not confirmed) by a Consolidated PBY Catalina on 7 June 1942.

After unsuccessful BETASOM patrols from 14 October to 13 November 1940 and from 10 February to 8 March 1941, Barbarigo damaged the British freighter Manchester Port on 15 May 1941.

After an unsuccessful patrol from 22 October to 12 November 1941, Barbarigo sank the neutral Spanish freighter Navemar on 23 January 1942.

On the following patrol, a similarly unsuccessful launch of torpedoes at the Flower-class corvette HMS Petunia was reported as the sinking of another battleship.

Barbarigo sank two Allied ships and another neutral Spanish freighter Monte Igueldo on its ninth BETASOM patrol.

[9] After conversion to a transport submarine, Barbarigo sailed from Bordeaux on 17 June 1943 and was sunk by aircraft in the Bay of Biscay.

After another unsuccessful BETASOM patrol, Emo sailed from Bordeaux on 20 August and passed the Strait of Gibraltar to return to Naples on 1 September 1941.

After spending two months as a training boat at the submarine school in Pula, Emo completed several Mediterranean war patrols before being sunk by the naval trawler HMS Lord Nuffield on 7 November 1942 during the preliminary stages of Operation Torch.

While returning to France after sinking another ship during a second patrol to the Caribbean Sea, Morosini was lost to unknown causes after 8 August 1942.

[13] Cappellini sailed on 11 May and reached Singapore on 13 July 1943 with 160 tons of mercury, aluminum, welding steel, 20mm guns, ammunition, bomb prototypes, bombsights and tank blueprints.