Original designed in 1934 for anti-submarine training, by the end of the war seventy-two U-Class subs had been commissioned. Seventeen were lost to the enemy and three in accidents. Manned by crews from seven nations' navies, they served world-wide and never more successfully than in the Med, where they made a major contribution to the defeat of Rommel's Afrika Corps. The quality of their service is born out by the 375 gallantry medals awarded to crewmen including Lt Cdr David Wanklyn's VC. AUTHOR: Born in Derbyshire Derek Walters served in the Royal Navy. He was on board the submarine Talent when she collided with a merchant ship in the Channel. He joined the Police on retirement. He writes for naval magazines. 32 b/w illustrations