London, Zack, Cody and Mr. Moseby set sail on the S.S. Tipton for their semester at sea. London convinces her roomate to leave the ship so she can have a room to herself. Cody finds himself sharing a room with Woody, who is very messy, and Zack shares a room with Bailey, who is a neat freak. Nobody knows that Bailey is a girl who disguised herself as a boy in order to gain a position on the ship after she found that there were no more vacancies for girls. Zack and Cody agree to switch roommates, but Zack changes his mind after he finds out that Bailey is a girl. After everyone else eventually finds this out Bailey is allowed to stay, filling the position vacated by London's ex-roommate, and Bailey becomes London's new roommate. This is the last straw for London and she escapes to Parrot Island via helicopter.

Chelsea, Barbara, and Bob visit the S.S Tipton. Cody is worried about how he's going to tell Barbara about his feelings for Bailey, but Barbara has to dump Cody because she and Bob are now dating. Right before Cody tells her about Bailey, Barbara tells him about her and Bob. To make Barbara jealous, Cody tells her that he and Bailey are also dating, thinking he can get away with the lie because Bailey is off the ship, but she returns early. London tells Chelsea that her room is her shoe closet, and that Woody is her servant. Woody agrees to help her because he has a crush on Chelsea. During movie night, Cody tries to make Barbara think that he and Bailey are dating, but Bailey eventually finds out. Cody apologizes and Bailey forgives him and says if he wanted her to be his pretend girlfriend, all he had to do is ask. To show it, she tickles him, wraps her arms around him, and finishes with a kiss on the cheek (causing Cody to faint) saying that would have made Barbara really jealous. Chelsea finds out that London is just a regular student, but instead of telling everyone, tells London she will tell everyone that London was "abducted by aliens" instead.

When Cody and Kirby don't allow Zack to bungee-jump off the side of the ship, the brothers accidentally knock Kirby off the ship, but Kirby lands in the hot tub. To make it up to him, Zack and Cody tutor Kirby so he can pass his high school equivalency exam to earn a better job. Meanwhile, London embarrasses Bailey on her internet show in a new segment called "Boo You!"

The boys plan to have an all-guys weekend with their dad, but a surprise visit from their mom ruins it. When Kurt and Carey get a show on the ship, Mr. Moseby says they can stay on board, but worried their parents will permanently stay on the ship, the twins hatch a plan to sabotage their parents' show. Meanwhile, London tries to find the perfect belated birthday gift for Mr. Moseby by following him around all day. In the end, London makes Mr. Moseby very happy that he got a present from her because even his own mother forgot his birthday.

After Kirby injures Moseby, Connie takes over Moseby's work and breaks a boat in a bottle intended as a gift for the captain. Everyone tries to comfort Moseby, but none of them do any good. Moseby overhears mention of a problem with the boat and thinks there is a problem with the full-size ship. London eventually fixes the boat in a bottle. Moseby falls down the stairs and injures everyone except London. Finally, Moseby accidentally breaks the boat and doesn't have enough time to repair it.

Hannah Montana boards the S.S. Tipton on her way to a concert performance in Honolulu. To impress Bailey, Cody desperately tries to get tickets to the show. Meanwhile, the Russo's are still aboard the ship on their vacation in which Alex pulls a prank on Justin by putting blue dye in the hot tub, making him turn blue, for which Mr. Moseby blames Zack, while Max tries to impress London with his magical suitcase.

The crossover starts on Wizards of Waverly Place S02E25 Cast-Away (To Another Show) (I). It continues on Hannah Montana S03E20 Super(stitious) Girl (III).

Zack is surprised to learn that he has a new roommate who used to be a famous rapper until he hit puberty and his voice got deep.