"Battleship Island" (戦艦の島, Senkan no Shima) is episode 226 of the Naruto: Shippūden anime.
While sailing towards the Land of Lightning, Naruto Uzumaki and the others are attacked by pirates who wanted to sink their ship and loot the wreckage. Thanks to some fast thinking on Yamato's part and the early warning by one of the sensor-type shinobi however, the ship is saved and they dock in an underground cavern. There they find a burial ground and a journal telling of the plight of the native islanders at the hand of the wicked Gataro and his men. Hearing this, Naruto vows revenge for the deceased and comes up with an ingenious strategy on how to escape the giant geyser that they were trapped in. Using Naruto's strategy the Konoha shinobi and crew were able to escape the island and put Gataro and his men out of commission.
When water is rushing in on the makeshift submarine Yamato made, he can be seen without his head gear and depicting a normal Konoha forehead protector.