The Young Man and the Sea

is episode 223 of the Naruto: Shippūden anime.

Summary
Tsunade sends out Naruto under the guise of a top-secret mission to keep him hidden away from the Akatsuki. Unfortunately, Naruto, Yamato, Guy, and Aoba are stuck at the pier due to a report of a monster attacking ships. They met Yūsuke, who wanted to avenge his father's death because of the marlin. On the next day, the helped him defeat the monster by giving equipment Yūsuke needed.

Trivia

 * The episode's name and story are probably based off Ernest Hemingway's novel, The Old Man and the Sea.