According to decrypted intercepts of German naval communications with Japan, U-864’s mission was to transport military equipment to Japan destined for the Japanese military industry, including approximately 67 tons of metallic mercury in 1,857 32 kg steel flasks stored in her keel.
Thanks for that info.
According to Underwater Times, the U-864 is at 150 meters and also carried Me-262 jet aircraft parts and 22 torpedoes. Could be dicey.