Popular representations of World War II often portray the drama that took place overseas. But a battle between German U-Boats and American and British ships happened off the North Carolina coast as well. The Germans sunk nearly 400 ships, including the H.M.S. Bedfordshire. This Friday is the 70th anniversary of its sinking. Host Frank Stasio talks to Kevin Duffus, author of “War Zone: World War II Off the North Carolina Coast” (Looking Glass Productions/2012), about the battle for sea supremacy in North Carolina waters during the confilct.