In 1942 German U-boats turned the shipping lanes off Cape Hatteras into a sea of death. Cruising up and down the U.S. eastern seaboard, they sank 259 ships, littering the waters with cargo and bodies. As astonished civilians witnessed explosions from American beaches, fighting men dubbed the area Torpedo Junction. And while the U.S. Navy failed to react, a handful of Coast Guard sailors scrambled to the front lines. Outgunned and out-maneuvered, they...