Continuing their journey to Mosdeep City, our friends are on a island. Everyone enjoys it out here. Brock sees two girls walking by and he gets all excited.

A shadow that's in the water starts to come up. Something pops out of the water. May thinks that it's a sea monster and Ash wonder if it's a Pokémon or not. The "monster" is wrapped up in seaweed and it's holding a bag. The thing drops its bag and reveals himself as a human. His name is Adam and he tells them that he is the man of the sea. He also tells them that he found buried treasure. Ash wonders what kind of treasure it is. Adam takes out emeralds out of the bag and May thinks that they are beautiful. Adam explains that he has a shop called Bounty of the Sea. Then Adam invites the gang to his shop.

At the shop, Adam introduces his wife, Evilin to the gang. Evilin is looking through a tiny microscope at the emeralds that Adam found. Evilin then explains to Adam that his find wasn't emeralds and that they are green shards. Ash asks what a green shard is and Evilin tells him that green shards were used for making jewelry. She tells Adam that green shards are worth more than sea shells, Feebas scales, and Crawdaunt claws. She tells Adam that green shards aren't worth much at all. Adam gets upset and the gang tells him not to get so hard on himself. Then Evilin says that the quality of the green shards are great. Adam then tells them that he hopes the shards are from the Wreck of the King Neptune. He explains the story about a sunken ship to them. Ash asks where he found the shards and Adam tells him that he found it on a Relicanth. Ash takes out his Pokédex and looks up Relicanth. Max then comments on how Relicanth is hard to find. Evilin then tells Adam to try to find the Relicanth again and Ash asks if they can go with him. Adam responds with a yes and they get the ship ready.

Team Rocket is beneath the bushes and they are listening in on their conversation. Team Rocket, of course, wants the sunken treasure too. They plan to have Ash and the others find the treasure and then they'll steal it. Meowth then tells another of his "boss" stories again. Team Rocket cheers at the end.

Back at the ship, everyone except for Evilin is in a submarine. Evilin is in a ship and her job is to make sure that everything's okay. When everything's ready, they dive into the water.

Evilin and Adam communicate a bit with each other. Adam then turns on the sub's lights and on the screen is Pokémon including Huntail and Wailmer. Max notices a group of Chinchou swimming along. On the screen comes a Relicanth.

Suddenly, they hear a big crash. Adam checks the rear view and a Magikarp is there - a gigantic one. Ash exclaims that that is Team Rocket's submarine. Evilin is listening in and it doesn't sound very good.

Team Rocket continues to pedal in their sub. Jessie is complaining that there is no motor in the sub. Then James gets an idea. He sends out his Chimecho thinking that it will calm Jessie and Meowth down. However, Meowth is still savage and fires two missiles at Adam's sub. The missiles hit the sub directly and a red light flashes. The Magikarp sub goes ahead of them. Adam tells Evilin that everything's okay.

Relicanth is going deeper into the sea and Team Rocket follows it. In the sub, Jessie says that she follow the Relicanth no matter how long it takes. Then water starts to leak in their sub. More water then bursts in the sub. Team Rocket's sub heads into the strong current and they are fastly moving away.

On the moniter, Ash and the others are watching the current. They then get an underwater turbulence that was created from the same current. Relicanth then dives into the current and Adam decides to go into the current as well. Evilin gets mad that they went into the current. Relicanth continues to go down the current and Adam continues to follow it. They start to do a bit of bouncing into the walls and everyone screams.

When everyone awakens, the sub is lit with a bright red light. Adam asks if everyone's okay. Pikachu jumps into Ash's arms. Everyone looks out the window and they see a big old ship. Everyone is then out of the sub and Adam is sure that that is King Neptune. Then Adam goes in to get the treasure. Max wonders of how there could be so much light in the cave. Ash sees an opening and thinks that air comes through that opening.

A Relicanth comes through an opening and a lot of other Relicanth are swimming along in the water. They comment on how the Relicanth were probably here since the ship sank. Then Adam comes out with the treasure under his foot. When Adam decides to open up the treasure, they hear a strange voice out of nowhere.

Team Rocket's sub appears above the water and they say their motto. When they are done with their motto, Meowth fires a plunge thing (or whatever you call it) and uses it to snatch the treasure from them. Adam gets angry and starts to charge at Team Rocket, but Meowth fires a missile. Everyone ducks and the missiles explode on the King Neptune ship. The missiles also destroyed the Relicanth's home. Then all of the Relicanth go to Team Rocket and they look very angry. Jessie fires a missile straight at the Relicanth, but Ash's Corphish uses Bubblebeam on the missiles. The missiles explode before they hit the Relicanth. Then Team Rocket decides to leave. They head back into the sub and they head out. Meowth then fires two more missiles back which closes up the entrance and exit.

Ash and the others wonders what to do because their exit is sealed. However, the Relicanth knows another exit and they decide to show Ash and the others the way out. They go back into the sub and decide to follow the Relicanth. On the screen, they see and underwater exit. To get to it, they have to go through another current. So they go through the current.

Evilin is still out there trying to get in contact with Adam. Adam tells Evilin that they are returning to surface and that everything's okay. When they return to surface, the kids thank the Relicanth for showing them the exit. Evilin gets a little angry that Adam never responded but she tells him that she's been tracking Team Rocket all this time.

At the shore, Team Rocket is out of the sub with the treasure. They plan to get some good money with the treasure. However, Ash and the others stands right in front of them with the Relicanth and Ash tells Team Rocket to give back the treasure. May takes her Bulbasaur out and Bulbasaur uses Vine Whip on the treasure. Team Rocket grabs the treasure and they tell them that they are crooks. Jessie takes out Seviper and Seviper does a Poison Tail attack on Bulbasaur. Bulbasaur falls backwards but Brock tells his Mudkip to use Water Gun. Mudkip uses Water Gun and the Relicanth use Hydro Pump on Team Rocket. Team Rocket falls to the ground and Bulbsaur grabs the treasure chest with its vines. Lastly, Pikachu uses Thunder which send Team Rocket flying.

Adam decides to open of the treasure chest and everyone wonders what's inside. So Adam opens up the treasure chest and it's full of green shards! Adam is disappointed that he only found green shards instead of real treasure. May thinks that the shards are beautiful and Evilin tells her that she will give her the first necklace that they finish. Adam then tells them that he will continue his quest in finding real treasure. Adam then wishes good luck to the Relicanth's quest in finding a new home. The narrator then says the last words that Ash and the others continue their journey to Mosdeep City.

English Official Summary

The kids are relaxing at the Grand Wazoo Resort on Wazoo Island when a man emerges from the water completely covered in seaweed. His name is Adam, and he is a treasure hunter who believes he has just uncovered the location of the King Neptune, a cargo ship that was wrecked long ago. Adam and the kids go searching for the wreck in a sub, secretly followed by Team Rocket in their Magikarp sub. Team Rocket fires a missile at them and zips ahead. Adam and the kids manage to find their way to the cavern where the ship is located, where lots of Relicanth have made their home. Adam finds a trunk. Team Rocket shows up again to take the trunk, also destroying the ship. Team Rocket then destroys the exit to the cave as they leave, and heads to the surface. Adam's sub follows the Relicanth out and catches up with Team Rocket. Angry at the destruction of their home, the Relicanth use Hydro Pump on Team Rocket, while Pikachu finishes them off with Thunder. Opening the trunk, Adam discovers that the King Neptune was only carrying lots of Green Shards. Aside from that, he does have one real treasure to show for this adventure—the friendship of the Relicanth.

French Official Summary

Les enfants se détendent dans la station balnéaire de Saint-Marthe lorsqu'un homme, complètement couvert d'algues, émerge de l'eau.

German Official Summary

Unsere Freunde entspannen sich im Erholungsgebiet auf der Wazoo-Insel als ein vollständig mit Tang bedeckter Mann aus dem Wasser steigt.

Italian Official Summary

I ragazzi si stanno rilassando in un celebre luogo di villeggiatura sull'Isola di Wazoo quando emerge dalle acque un uomo completamente ricoperto di alghe.

Portuguese Official Summary

Ash e seus amigos se unem a um caçador de tesouros para explorar as profundezas do oceano, mas a Equipe Rocket está logo atrás deles!

Finnish Official Summary

Ash ystävineen lähtee aarteenetsijän mukaan tutkimaan merta, mutta Rakettiryhmä on heidän kannoillaan!

Spanish Latin America Official Summary

Ash y sus amigos se unen a un buscador de tesoros para explorar el mar profundo, ¡pero el Equipo Rocket está justo detrás de ellos!

Spanish Official Summary

Los chicos se relajan en el centro turístico Wazoo de Isla Wazoo, cuando de repente un hombre sale del agua completamente cubierto de algas marinas.

English Great Britian Official Summary

The kids are relaxing at the Grand Wazoo Resort on Wazoo Island when a man emerges from the water completely covered in seaweed. His name is Adam, and he is a treasure hunter who believes he has just uncovered the location of the King Neptune, a cargo ship that was wrecked long ago. Adam and the kids go searching for the wreck in a sub, secretly followed by Team Rocket in their Magikarp sub. Team Rocket fires a missile at them and zips ahead. Adam and the kids manage to find their way to the cavern where the ship is located, where lots of Relicanth have made their home. Adam finds a trunk. Team Rocket shows up again to take the trunk, also destroying the ship. Team Rocket then destroys the exit to the cave as they leave, and heads to the surface. Adam's sub follows the Relicanth out and catches up with Team Rocket. Angry at the destruction of their home, the Relicanth use Hydro Pump on Team Rocket, while Pikachu finishes them off with Thunder. Opening the trunk, Adam discovers that the King Neptune was only carrying lots of Green Shards. Aside from that, he does have one real treasure to show for this adventure—the friendship of the Relicanth.

Russian Official Summary

Искатель сокровищ заинтересовывает Эша и его друзей своими подводными поисками и тем, что считает своей величайшей морской находкой. Наши герои с радостью бросаются на разгадку тайны покемонов, и следуют за древним покемоном Реликантом, который, по мнению искателя сокровищ, приведёт их к богатству. Но, ведомая жадностью Команда Р, следует за ними и ждёт удобного случая для нападения. Наши герои смело опускаются на морское дно.

Dutch Official Summary

Ash en zijn vrienden sluiten zich aan bij een schatzoeker om de zeebodem te onderzoeken, maar Team Rocket zit ze op de hielen!

Norwegian Official Summary

Ash og vennene hans blir med en som er på skattejakt for å utforske havets dyp, men Team Rocket er rett bak dem!

Swedish Official Summary

Ash och hans vänner följer med en skattjägare för att utforska havets djup, men Team Rocket är dem tätt i hälarna!

Danish Official Summary

Ash og hans venner tager med en skattejæger ud for at udforske havet, men Team Rocket er lige i hælene på dem!