USS Tunny was observed by a Japanese ship 40 kilometers off of Truk, Caroline Islands, but there was no subsequent attack. Early in the afternoon, she intercepted Japanese submarine I-9; she fired three forward torpedoes, and the Japanese submarines fired two; all torpedoes missed. Japanese aircraft arrived to hunt USS Tunny, but the bombs dropped caused no damage. USS Tunny would remain submerged until sundown. After dark, while on the surface, she made radar contact with a Japanese destroyer; as she moved to attack, the destroyer also detected her, attacking with nine depth charges; Tunny would remain submerged for hours to escape the attack.
