Episode Special 1

Adventure in the Ocean's Navel is the first TV Special of the One Piece anime. It was aired after episode 52 of the anime.

The storyline time assumed to be placed between the Loguetown Arc and Warship Island Arc.

Short Summary
Luffy finds a chest, with a skull inside with an engraving about a treasure. The Straw Hats then explore a crater in the sea, but end up in a ship graveyard and encounter a bat, who warns them of 4 monsters.

Long Summary
It is another peaceful day on board the Going Merry. Nami yells at Luffy for urinating in the ocean, as it'll just contaminate the fish that are swimming. Luffy is on fishing duty, but he is using sponges for bait, which he sees them to look like hamburgers. Nami can not believe how naive Luffy is, until he catches something big, and it drags the ship backwards instead of forwards. The fishing line ends up at a rocky crater with a chest being chained to it.

Luffy is disappointed that it wasn't something to eat, but Nami is more interested in finding out what's inside the chest. She opens it only to find just a skull inside. Usopp reads the back of the skull, which engraves about a treasure that can make anyone's dream come true. It lies deep in the ocean's naval. Then a large hole begins to form near the crater they crashed into, so Usopp, Nami, and Sanji prepare themselves in a diving barrel to explore the cavity in the sea. Luffy is put in charge of the rope crank.

It is a smooth ride, for the trio in the barrel, right until Luffy gets side tracked and finds a flying message in the bottle, which he becomes disappointed that it wasn't a drink. Then the diving barrel begins to fall faster into the naval. Usopp uses the hose communicator to warn Luffy that they're in danger.

Luffy manages to get hold of the rope, and the barrel barely crashes into the surface of the naval. Usopp, Nami, and Sanji find themselves in a ship graveyard, and are greeted by a laughing bat who says he will guide them to the treasure - the treasure that Captain Joke tried to steal one decade ago. Then Nami and Usopp realized that a huge monster was after them, which terrified them. Fortunately, Sanji started fighting the monster, but he didn't manage to kill it. The monster was finally killed when the Going Merry fell on it. After that incident, Nami and Usopp decided to try to find the treasure while Sanji stayed behind because he was unable to move due to his fight with the monster.

Elsewhere, a kid, Hamu, was sending letters in bottles but he was told to stop by Meroie because even if somebody received a letter, he wouldn't go down there to save them. Despite that, Hamu refused to stop because he needed friends in order to save his village. Suddenly, their bell rang and when they opened the door they saw Zoro trying to save Luffy, who had already fainted due to his weakness to water. They are about to welcome the men but a monster attacks them. Zoro gather all his strength and stops the monster with a polearm and he later attacks the monster with it.

Then Hamu and Meroie give them food and Hamu asks them about his letters and the reason why they are there. Luffy replies that he can't read they latter and he explains that they are there because they fell while looking for a treasure, admitting that they are pirates. That made Hamu angry and disappointed because he thought that they were the friends he was waiting for. Then Hamu leaves the house and visits his mother's tomb while Luffy and Zoro ask Meroia about the village's past. She explains that captain Joke and his crew came there ten years ago and destroyed the entire village till they finally decided to go to the Mountain of God where all their wishes would come true. She also explains that Hamu's mother was killed by Joke when she tried to stop them all bu herself. After her death, Meroie looks after Hamu.