 The last two remaining U-boats left Bordeaux in August 1944, three days before the Allies occupied the base on 25 August.The last remaining German naval personnel attempted to march back to Germany but were captured by US forces on 11 September 1944.In 1940, all twenty-eight Italian submarines which were to be based at BETASOM initially had to sail from bases on the Mediterranean Sea and transit the Straits of Gibraltar to reach the Atlantic Ocean.