Naruto gets scared easily. Yamato, deciding to have some fun with him, told a story of an old ship with large devil fire lighting on the top of its mast. Led by crows this ship cruises through foggy nights guiding the souls of the dead. If you come across it you're doomed to a journey by sea to the land of the dead. "The Cursed Ghost Ship" is the title of the next episode of Naruto Shippuden 225.
Just as Yamato dropped the ball telling Naruto that it was just a tail, dead soul ship, just like the one Yamato described, appeared. Yamato and Aoba boarded the ghost ship. Naruto gathered some courage and went onboard as well. Looking for those two he bumped into Hishaku.
Hishaku claims that fire on the mast is just a sign of good luck and there is no such thing as ghost ship. That glow around the ship, well that's just static discharge of electricity. Those are no crows, but seabirds taking a rest. No ghost ship, but when Hishaku was asked where his captain and crew were he said that there is a monster. Skeleton Crab is huge monster with barnacles attached on a hard shell and if you get caught between its pinchers, it's over.
At that moment Yamato was snatched and taken away by this crab. Naruto jumped to action using his Rasengan tried but failed to attack crab's shell. Hishaku got the ship moving and when huge rock appeared he made sure to stir directly into it. Crab got pinched between the ship and this rock. Naruto going at it again with his rasengan and a broom he borrowed from Hishaku, he was able to kill this monster.
Hishaku appeared once more to thank Naruto for avenging him and his crew. Soon after he disappeared. He was along with his crew a ghost and this ship truly was a ghost ship. Hishaku, along with the ship disappeared in front of Naruto's eyes.
Naruto and his crew sail on, only to enter a huge storm. Rudder stops working and ship gets carried away by a strong current. Something gets in their way. The title of next episode of Naruto Shippuden 226 is "Battleship Island".