When Hitler's Submarines Ruled in World War II. From Commodore to Cabin Boy, the story of Convoy SC7 is one of grim endurance and human courage in the face of almost incredible destruction. These are the accounts from the Naval Escorts, the Merchant Masters and even a German U-boat Ace. It is the sense of immediacy that makes these books so fresh and sometimes deeply moving. In their research, they are certainly brilliantly accurate and totally revealing in detail.