The most surprising find was the first-ever discovery of underwater aircraft that had flown on the Midway battlefield, NOAA said. Previous missions have investigated ships that took part in the battle, but the dive on April 20 found aircraft that had engaged in the air and sea battle.

The USS Yorktown retrieved two Enterprise aircraft that were damaged in an attack on the Japanese navy carrier Kaga, according to the agency, citing records. The planes were moved down to the hangar deck before they caught fire when underwater missiles by the Japanese pounded the ship.