Sins of the Father. Clifton Chronicles 2: Jeffrey Archer

It is only days before Britain declares war on Germany. Harry Clifton, hoping to escape the consequences of a familyscandal, and realizinghe can never marry Emma Barrington, has joined the Merchant Navy. Whena German U-boat sinks his ship, Harry and a handful of sailors are rescued by the SS Kansas Star, among them an American named Tom Bradshaw. That night, when Bradshaw dies, Harry seizes a chance to bury his past-by assumingthe man's identity.