A World War II submarine that sunk with 80 sailors on board and was missing for 75 years, has now been found by an expedition team.

On Sunday, undersea explorer Tim Taylor and his team at the Lost 52 Project announced they located the USS Grayback on June 5, buried almost 1,400 feet underwater, about 50 miles south of Okinawa, Japan.

The sub was sunk in February 1944 by a Nakajima b5N carrier bomber, while on a mission in the East China sea, according to a video announcement from the Lost 52 Project. The sub had sunk 21,594 tons of shipping on its final mission alone, and overall, the submarine is credited with sinking 14 ships with 63,835 tons of cargo, according to Naval History and Heritage Command.

To unravel the mystery of the long-lost submarine, Taylor relied on Yutaka Iwasaki, a system engineer who studied the original Japanese military documents and discovered that the Navy’s translation of the coordination was wrong.

“It was off by one digit,” Taylor told the Washington Post. “That changed the location by more than 100 miles.”

With the correct information, underwater vehicles and advanced imaging technology, the team discovered the Grayback about 100 miles from the area they first thought it would have sunk.

“The confirmation of the site as a U.S. Navy sunken military craft ensures it is protected from disturbance, safeguarding the final resting place of our sailors,” head of Naval History and Heritage Command’s underwater archaeology branch, Robert S. Neyland, said in a statement.

The discovery also brought a mental closure to friends and families of the sailors present on the submarine when it sunk.

On Jan. 28, 1944, the USS Grayback set sail from Pearl Harbour for the East China Sea. A month later, the submarine reported sinking two Japanese cargo ships. Though the Grayback was scheduled to arrive in March, more than three weeks passed without sight of the submarine. On March 30, 1944, the Grayback, one of the most successful submarines of World War II, was reported lost.