Sink or Swim is the 68th episode of The Suite Life of Zack & Cody. The tabloids report London doesn't know how to swim, so she takes swimming lessons. Zack has been offered to work at the hotel as a plumber or to work at a local market.
Zack is finished with summer school, and finally truly graduated middle school. Seeing that Cody is working at the Paul Revere Mini Mart, Zack decides he wants to work as well. Arwin asks Zack if he would work with him, and Zack quickly agrees. First off, Zack isn't really interested in the whole 'work' thing. And doing Arwin's disgusting jobs (such as unclogging a pipe, with goo falling all over them) eventually drives Zack insane.
Arwin sends Zack to get some bleach (or "blech", as Zack calls it). He takes as much time as possible hanging out at the mini-mart. Zack wants a better job, and Cody knows that the mini-mart has an opening. But he decides not to tell Zack, because he is too aggravated with Zack.
Zack returns from the mini-mart... the next day. Arwin is bad with disciplining, so he lets Zack slack off. Suddenly, a pipe bursts in Arwin's office, and he sends Zack to find something to plug the hole. Zack, of course, goes to the mini-mart. Zack returns hours later, and tells Arwin they were all out of duct tape. So he just got it from Arwin's desk. Arwin finally attempts to discipline Zack, but goes crazy as he does it. After their little talk, Arwin says he is going to go seek anger management classes. He leaves Zack with a new pool filter, and tells him to change it while he's gone. Zack gets a paper cut, and leaves because he doesn't want it to be infected.
Meanwhile, the girls at Camp Heaven-On-Earth have been using Maddie's connection to London to sell tips to the Global Enquirer. With the money, they’ve been able to buy many nice things. Maddie eventually finds out, but due to London's rude comment about her hair, she goes along with the plan. So throughout the episode, they continue getting information from London.
At the same time, the tabloids discover that London - the owner of an overpriced swimsuit line - can't swim. She says it was something she never saw necessary to learn, similar to learning the ABC's. So she seeks help from the dorky lifeguard Lance. They quickly fall in love. As they jump into the main pool at the Tipton (they had been practicing, of course, in London's own swimming pool), the pool is filled with sludge because Zack never changed the filter. Arwin takes the blame when Moseby asks, but does not let Zack off the hook completely. Zack tries to apologize, but gets angry.
The next morning, Arwin goes to the pool to begin cleaning out the mess, but he finds out that Zack fixed it, and that the expenses would be taken out of Carey's paycheck. They eventually agree that the job is not quite right for Zack. Later in the day, Zack is at the mini-mart, and when a girl asks Zack if he knows where bread is, he replies suavely, and Cody's boss asks Zack to join their work force. Zack finds out that the position was open all week, and chases Cody around the store.
- "And that’s why we don’t play soccer with a bee hive!” - Maddie Fitzpatrick.
- "Yes! Sticker doodles, thankyou mother." - Arwin Hawkhauser.
- "A magazine, it’s $2:49." - Millicent.
- "Don't be a chicken, ducky." - Lance Fishman.
- "I just dove into 10 feet of goo. Who is responsible for that?" - London Tipton.
- "EWWWWWWWW" - London Tipton.
- "You're Paying for my Dry Cleaning, and My Facialist, and My Dirty Ducky" - London Tipton.
- " I Have to go now My Favorite Show is on" - Cody
- The sludge that spills on Zack and Arwin closely resembles the slime at all Nickelodeon Kids Choice Awards.
- London and Lance get covered in Goo because they swam in the pool when Zack never changed the filter.