u777U-777 was a Type VIIC submarine that served in the 31st Flottille from May to October 1944. It was sunk by bombs at Wilhelmshaven and later scuttled in 1945.U-777 was a Type VIIC submarine that served in the 31st Flottille from May to October 1944. It was sunk by bombs at Wilhelmshaven and later scuttled in 1945.