For sale is a copy of the hardcover book, "The Naval War Against Hitler," (1971) Donald McIntyre.  As the author points out, but for naval superiority, the Normandy landings wouldn't have been possible or the evacuation at Dunkirk.  Keeping Britain fed and armed crossing the treacherous Atlantic, dodging U-Boats, was no easy feat and victory against Germany might not have happened without control of the waterways.  The book has 478 pages.