December 11, 1941: Hitler declares war against America. For German Admiral Karl Donitz, Commander of the U-boat submarine fleet, the time is at hand. Donitz devises a plan for a surprise attack on the U.S. Atlantic Seaboard, called “Operation Drumbeat”. The message to the United States is clear; Hitler is coming… This story, one of the most deadly attacks off America’s East Coast, is covered up and remains largely untold and secreted away for over 60 years —until now. For the first time, the story of these U-boats and their prey is being hunted down, uncovered and filmed by NOAA National Marine Sanctuaries. Using advanced Hi-Def ROV’s, side scan sonar, and 3D imaging, this show will piece together the tactics, battles, heroes & villains of, “Operation Drumbeat”, one of the most unknown and deadliest attacks on the U.S in history.