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 worldwide and never more successfully than in the Mediterranean, 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.