Though German naval forces were a significant threat during this high-level seaborne meeting, the British Admiralty sent U.S. Navy leaders "estimates" of U-boat locations that were extremely detailed and current. Using that information to avoid contact with German forces, Roosevelt and his party sailed USS Augusta (CA 31) to rendezvous with Prime Minister Winston Churchill aboard HMS Prince of Wales at Placentia Bay. Churchill had sailed from Scapa Flow aboard Prince of Wales to meet with Roosevelt directly and discuss Britain's long-term naval strategy for fighting Germany. The two leaders likely shared some highly sensitive intelligence secrets with one another during the Argentia Conference. Shortly after this symbolic meeting, Churchill and Roosevelt published a joint declaration known as the "Atlantic Charter," a non-binding unified Anglo-American statement against German aggression on the high seas. American Chairman of the Joint Chiefs of Staff General George C. Marshall is seen speaking with President Roosevelt. Meanwhile, U.S. Navy admirals Ernest J. King and Harold R. "Betty" Stark are standing behind the prime minister. In December 1941, King replaced Stark as Chief of Naval Operations.