A 75-year mystery is laid to rest this Veteran’s Day following the discovery of the USS Grayback (SS-208), an established World War II submarine that disappeared in 1944 with 80 crewmembers onboard.
A video shared to YouTube by the Lost 52 Project, an organization dedicated to locating lost US WWII submarines, announced the discovery of the tambor-class submarine named for a fish found in the US Great Lakes. It is the first to be discovered off the coast of Japan and is located 435 meters (more than 1,400 feet) deep about 50 nautical miles south of Okinawa, Japan.
USS Grayback had a successful military career, sinking more than a dozen Japanese ships during its three-year service. The submarine was first launched on January 31, 1941, and would go on to serve nine combat patrols. The 94-meter (307-foot) submarine left Pearl Harbor for its tenth combat patrol in January 1944 and was listed as missing by the Navy after it failed to return by late March. Official Japanese records noted that the Grayback “exploded and sank immediately” after being hit by a 227-kilogram (500-pound) bomb released by a Nakajima B5-N Carrier bomber, according to the Naval History and Heritage Command.
But that is precisely where the mystery began. After the war, the Navy worked to piece together the history of how, when, and where 52 of its submarines disappeared by using Japanese war records that contained approximate locations of the vessels, reports the New York Times. It was thought that the ship had sunk 160 kilometers (100 miles) east-southeast of Okinawa, but the latitude and longitude coordinates were off by one digit due to a mistake in translation. An analysis of radio records last year allowed researchers to find the correct coordinates and pursue an exploratory mission in June.
Explorer Tim Taylor and his crew used an autonomous underwater vehicle (AUV) to dive a few hundred feet above the bottom of the ocean floor while recording sonar data in 24-hour increments. When the AUV returned to the ship, researchers downloaded and analyzed data collected during the dive. It wasn’t until the “last quarter” of the last survey line that explorers saw two anomalies on the bottom of the ocean, after which point they deployed a remotely operated vehicle (ROV) that is directed from aboard the vessel and equipped with real-time video, leading to the discovery of the Grayback in a matter of hours.
"Each discovery of a sunken craft is an opportunity to remember and honor the service of our Sailors. Knowing their final resting place brings closure, in some part, to their families and shipmates as well as enables our team to better understand the circumstances in which the boat was lost," said Robert Neyland, Naval History and Heritage Command's Underwater Archaeology Branch Head, in a statement emailed to IFLScience. "We're grateful for the respectful, non-intrusive work Tim Taylor's team performs and the opportunity they provide to remember and honor our history."
Video shows the decayed vessel resting along the sediment as various species of fish swim along its decks and through its halls. More than 100 meters (more than 330 feet) away rests the submarine’s deck gun.
Its successful military career awarded the Grayback two Navy Unit Commendations and eight battle stars for her service. A special commemorative service was held to honor the memory of those who lost their lives in the battle.