- “I'm Mack.”
- ―Mack introducing herself
McKenzie, often called Mack, is the protagonist of Teen Beach Movie.
McKenzie is a surfer who is very passionate about it and loves to surf. She loves spending time surfing and hanging out with her boyfriend Brady. She also does not seem to be a fan of musicals. It is revealed that McKenzie's mother died prior to the film's events. She is living with her aunt. Her father is not mentioned. McKenzie's mother always wished for McKenzie to attend a prestigious college and to focus on her studies, not surfing, when it is time. McKenzie promised her mother she would and throughout the movie struggles to keep that promise.
McKenzie is a smart and confident girl with a competitive side. Mack is really passionate about surfing. She can also be very serious when she needs to be. When she and Brady get trapped in Wet Side Story, McKenzie is serious about it and is focused on getting home.
In the movie, after a surfing accident, McKenzie gets trapped into her boyfriend Brady's favorite musical, Wet Side Story, along with Brady. Brady is ecstatic for endless summer, but McKenzie just wants to get home so she can keep her promise to her aunt about going to college when it is time, fulfilling her mother's wishes. She says that every minute she is there, she is not doing what her mom wanted.
Soon, when at Big Mama's hang out, Mack accidentally changes the movie when she bumps into Tanner, the movie's leading surfer, who catches her. Since she fell into his arms, Tanner falls in love with her instead of the movie's intended love interest, Lela. Now, Mack fears that her fate will be changed forever, especially when she finds herself randomly singing, morphing into the movie.