More than any other place in the United States, North Carolina serves as a uniquely accessible underwater museum and memorial to WWII’s Battle of the Atlantic. Since 2008, NOAA’s Monitor National Marine Sanctuary and partners have documented and surveyed this unique collection of WWII Allied and German vessels. NOAA’s goal is to protect these fragile historic resources for future generations, and to preserve the memory of the brave Allied service men and U.S. merchant mariners who fought to rid the world of tyranny. This presentation will discuss the danger posed by German U-boats during the Battle of the Atlantic along the Mid-Atlantic coast, their effect on Allied shipping, and the naval adaptations and convoy system that finally ended the U-boat threat.