Battle Aboard the St. Anne (Japanese: サントアンヌごうのたたかい！ Battle of the St. Anne!) is the 15th episode of Pokémon: Indigo League.
As a plan of their boss, Team Rocket give the heroes tickets to the cruise ship, St. Anne. On the ship, Ash battles a gentleman and almost wins. Seeing the potentional, the gentleman offers him a trade for Butterfree. Meanwhile, James buys a Magikarp and while Jessie and Meowth believe he got fooled, he knows that it is more to it. The members of Team Rocket attack the trainers and while they are defeated, the ship begins to sink...
After earning the Thunder Badge, Ash, Misty, and Brock walk across a bridge and they spot a luxury liner ship in the distance. After taking a closer look at it, they really want to go on it. But Brock says they don't have enough money to buy any tickets. They walk away sadly. However, Jessie and James, in disguise (dressing up as girls, including James), give them tickets to board the ship and invite them to join a Pokémon Trainer on the ship, the St. Anne. When Jessie and James are pleaing thermselve at what they had done and James delighted says "Oh wow, don't I make like the coolest girl?" Jessie get annoyed and slams James on the head with a hammer and tells him "Stop acting like an ignoramus!" and drags James away. Jessie and James go a lighthouse nearby to meet Meowth. They go to a phone to call their boss. Meowth notices that Giovanni has a Persian with him, making Meowth jealous about being replaced. Team Rocket tell their plan to Giovanni: invite a bunch of Trainers aboard the St. Anne and steal their Pokémon.
Ash, Misty, and Brock get on board the St. Anne and they go into the main room. They notice all of the people, their Pokémon, and Pokémon merchandise. Ash sees a battle between a Starmie and a Raticate. The Raticate uses Super Fang to break Stamie's jewel, giving Raticate the win. Ash steps forward to challenge the Raticate's Trainer, sending out Butterfree. Raticate attacks with Hi Jump Kick and Butterfree counters it with Tackle . Raticate uses Hyper Fang, but Butterfree stops it with Stun Spore. Just as Ash is about to win, the Trainer recalls Raticate, calling the battle a draw. Meanwhile, James walks by the salesmen. One of them convinces him to buy a Magikarp by tricking him into thinking its a valuable Pokémon.
As Ash and his friends are eating, the ship sails out of Vermilion City. The Trainer Ash battled earlier comes up to him and explains that he was impressed with Butterfree and would like to trade his Raticate for Butterfree. Ash asks Brock if he should trade Butterfree but Brock is focused on the girl next to him. Ash decides to trade Butterfree. Ash and the Trainer go over to a trade machine to trade their Pokémon. Ash gets the Raticate and the Trainer gets Butterfree. A little ways away, Jessie and Meowth ask James why he bought the Magikarp. James tells them that its a rare Pokémon. To prove this, he shows them its gold Poké Ball. Meowth points out the gold on the Poké Ball was sprayed on. Jessie asks James how he afford it. James says that his salary was so small, he used Jessie's salary to buy it. She yells at him and makes him return it. Meanwhile, Misty notices Ash looking out at the sea, wondering if trading Butterfree was the right choice. He tells Misty when he was trading Butterfree, he remembered all the good times they had together.
Team Rocket's plan starts, with the room everyone is in being locked up and the Trainers are forced to give their Pokémon to Team Rocket Grunts. Ash tells Pikachu to use ThunderShock on one of the Grunts. This inspires all the other Trainers to fight back with their Pokémon. Ash sends out Bulbasaur, Charmander, and Squirtle to fight the Grunts. Brock sends out his Geodude to fight too. Ash tries to sends out Butterfree, but Misty reminds him he traded Butterfree away. He watches Butterfree and its new Trainer fighting the Grunts sadly.
A group of Pikachu uses Thunderbolt to send Team Rocket flying. The ship sails into a big storm. James drops the Poké Ball Magikarp is in and runs after it. Ash finds the Trainer he traded Butterfree to and asks if he can trade back. The Trainer agrees and they reverse trade. The captain of the ship tells everyone the ship is unsinkable. A wave knocks the captain into a lifeboat and everyone scrambles to get into the lifeboats. Misty and Brock find Ash finishing the trade and Ash drops his Poké Ball and the three of them run after it. They get the Poké Ball, but a wave knocks them against a wall, knocking them unconscious. James, Jessie, and Meowth get Magikarp's Poké Ball, but another wave knocks them out also. They are all stuck on the ship when it sinks while the rest of the passengers get to safety. The captain believes everyone is safe, not knowing that Ash, his friends, and Team Rocket are still on the ship but still alive.
- "Just imagine, sunbathing on deck all day, just a nice long, relaxing cruise." - Misty
- "We could never afford a cruise like that." - Brock
- "Augh." - Misty
- "Reality can really bum you out." - Ash
- "Do you know anybody who says "radical" anymore?" - Ash about outdated slang
- "Like wow, don't I make like the coolest girl?" - James
- "Stop acting like an ignoramus." - Jessie
- "Ow." - James
- "I normally charge $100 but for you I'll throw in an egg-laying set, child-care set and an education set for only $300. How about it?" - Magikarp Salesmen
- "I'LL TAKE IT!" - James
- "I can tell, haha, you're going to be a very rich man, a very rich man." — Magikarp Salesmen
- "You idiot! Can't you see you were tricked?!" - Jessie
- "What a dope!" - Meowth
- "But you don't understand, Magikarp is a gold mine. Even its Poké Ball is solid gold."
- "It's just gold plated!" - Meowth
- "Magikarp is a no-talent Pokemon that can do nothing but flop around how do you expect to sell it?!" - Jessie
- "I was tricked." - James
- "How did you get the money for it?" - Jessie
- "Well, the advance on my salary didn't quite cover it so I..." - James
- "So you did what?" - Jessie
- "I used the advance on your salary." - James
- "You go return that fish and get my money back right now!" - Jessie
- "Are you crazy?" - Jessie
- "But I..." - James
- "WE GOT WORK TO DO!" - Jessie
- "Now there's no reason to panic. I just thought I'd test out one of the lifeboats." - The Captain
- "Wait! There goes my next paycheck!" - James
- "Who cares about your paycheck, what about mine?" - Jessie
- The "Who's that Pokémon?" of this episode is Raticate.
- The captain of the St. Anne decided to leave the ship first, even though it's usually customary for captains to leave last, so as to ensure that all passengers and crew have been evacuated.
- James and Jessie disguised themselves as Ganguro Girls at the beginning of the episode, though technically Jessie had orange hair.
- This is the first of few episodes where James cross-dresses as a girl.
- Aside from Misty and Jessie, Rachael Lillis also voiced the lady accompanying the Gentleman.
- The trade machine had the same buttons as a VCR.
- This the first time that Ash battled a large group of Team Rocket Members.
Raticate used Jump Kick, a move it can't learn.
- The gentleman having a southern accent was dub only.
- In the original, Jessie says that the ticket for the St. Anne was a present (even going as far to spell it as "P-re-s-en-t", while in the dub she says that they're "Totally free, To-tal-ly free".