For the gray wolves, are the happy times ... and very complicated moments for the allied sailors, especially in front of the American coasts. This is the inexorable rise of the U Bootwaffe reminiscent of dramatic memories. It is also the appearance of the embedded radar, the Huff Duff and many other technological answers that allow the Allies not to lose their footing. The disappearance of three of the greatest Aces of the submarine weapon is also the sign of the difficulties ahead for German sailors. A difficult and uncertain time for all the camps.