The author couldn't decide whether to write a history of the U-boat attacks along the American coast or a biographical account of a German sub commander and the pilot who sank his sub — so he tried to write both. The more broad-ranging history is written in a dull manner consisting mostly of numbers and ship names and doesn't even come close to giving a comprehensive account. The man-vs.-man part is somewhat better written, but is only one small part of the overall story and not enough in itself to be worth a book.