The sub that the researchers and technicians were searching for was the U.S.S. Grayback, or S.S.-208 as it was less lyrically known. And this salvage operation was carried out on behalf of the Lost 52 Project, which is dedicated to locating the 52 U.S. submarines that disappeared in WWII. The U.S. Navy had previously posted the Grayback as missing in late March 1944.