In "The Suite Life on Deck," Dylan and Cole are back as Zack and Cody, but now they're living on a cruise ship instead of in a hotel. It's High School at Sea, and the boys, along with London Tipton (Brenda Song) are attending the program and living aboard the SS Tipton, a luxury cruise liner owned by London's father. Along for the ride are Mr. Moseby (Phill Lewis) to manage the ship, and his niece Mia (Giovonnie Samuels).

The series introduces new characters as roommates for each of the boys and for London. That's right, London has to rough it in close quarters with a roommate and less closet space. But some things never change, and Zack and Cody will continue to get into mischief on the high seas of high school.