Episode #212 - Mantine Overboard!
Ash and friends run to catch the ferry for Red Rock Isle, but they just miss it. A man informs them that the ferry only leaves once a day and they'll have to wait. Dejected, they sit on the pier and plan what to do, when a woman walks up and overhears their conversation. Her name is Luca, she's studying the water Pokemon in the area. Brock flirts with her and volunteers to help her research, and Misty drags him away. Amused, Luca offers them all a lift in her boat. Nobody sees Team Rocket spying on them from a Magikarp submarine.
On Luca's boat, the kids notice diving gear and an old sea map. She explains that her great-grandfather was a researcher of water Pokemon. One day she found the map and his journal, which described his discovery of the Silver Wing, an artifact that could help uncover a mysterious Pokemon. However his ship was caught in a whirlpool and sank. The crew survived but nobody believed their story, and the wreck was never found. Now Luca is determined to clear her ancestor's name. With the help of a computer she has found where the ship is.
Team Rocket listens in, they will wait until the twerps get the treasure, then steal it and Pikachu.
Luca and Ash get into diving gear and jump into the water with Luca's three Magikarp. Pikachu is a bit disappointed at being left behind. They swim down and find the wreck, only to see that it's being guarded by a Mantine. Returning to the ship, they discuss using Pikachu to distract the Mantine while Luca sneaks aboard and gets the treasure. So Pikachu is fitted with his own little diving outfit and joins them. The plan goes smoothly and Pikachu is about to shock the Mantine when he's attacked by a Remoraid. Inside the wreck, Luca also meets a Remoraid and is forced to retreat.
Team Rocket is impressed by these Pokemon and decide to capture them instead of Pikachu.
After a break, Misty and Ash release their water Pokemon to help. Team Rocket's sub provides an excellent distraction for the Mantine, allowing Luca, Ash, and Misty to swim inside the wreck. There they encounter a school of baby Remoraid, and they think the other two must be the parents. Team Rocket gets past the Mantine and the sub rams the side of the wreck. The Remoraid are scared away, and the treasure chest is revealed!
Luca picks up the chest and they all turn to leave, to discover their way blocked by the sub. It extends a robot arm and grabs the chest, then moves away. The Mantine attempts to attack, but Meowth uses the sub's long tongue-like attachment to catch it. The Remoraid move in, freeing the Mantine and attacking the sub. Luca theorizes that the Pokemon live in a symbiotic relationship: they help each other out.
The sub spits out a net and captures the Pokemon, but Totodile and Corsola free them. Team Rocket decides to flee with the treasure instead, but Mantine helps Ash and Pikachu get close enough to the submarine to shock it, which destroys it and sends Team Rocket blasting off. Ash catches the treasure chest.
Back on the boat, Luca opens the chest to find a small silver wing-like shape. (It resembles Lugia's wings). Now she can prove her great-grandfather's story and find more clues about the mysterious Pokemon. In gratitude she gives our heroes a lift to Red Rock Isle.