“Shadow Divers,” by Robert Kurson, is the true adventure of two Americans who risked everything to solve one of the last mysteries of WWII. In the fall of 1991, divers found a German U-boat 230 feet below the frigid Atlantic surface, 60 miles off the coast of New Jersey. Official records all agreed that there simply could not be a sunken U-boat and crew at that location. Over the next six years, an elite team of divers embarked on a quest to solve the mystery. Library. Members +1.