Exercise CD rehearses a German raider breakout

Exercise CD used a thinly disguised scenario in which a hostile surface raider tried to break westward into the Atlantic. Southampton successfully played the escaping ship, even confusing reconnaissance aircraft by signaling as Admiral Graf Spee, while the other Towns practiced finding the threat. The participation of carriers, battleships, cruisers, and aircraft made the rehearsal a fleet problem rather than a simple cruiser chase. The wider exercise program also explored Channel interception and coordination between ships and aircraft.