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, and they must defeat the 4 large aquatic monsters that were awaken when Joke tried to steal it for himself. Will Luffy and Zoro make it in time to aid their friends? Will they be able to defeat the mammoth monsters? And who is the bat who is driving everyone batty with his laugh?