Ben Cronin (Bradford) has got it made. He's a high school swim champion about to get picked up by Stanford University's sports scouts, girlfriend Amy (Appleby) adores him, and he's the most popular kid in his class.
Everything's great... until he meets his number one fan, new girl Madison (Christensen), who seduces him into having some underwater nookie in the swimming pool.
She tells him it's just a one-night stand, but he's barely zipped up his pants before she's following him everywhere, filling his inbox with emails, and threatening to tell his girlfriend about their little secret.
With its trio of fresh-faced youngsters (Christensen played Michael Douglas' drug-addled daughter in "Traffic", Appleby's best known for Roswell, and Bradford's a teen heartthrob from "Bring it On"), "Swimfan" desperately tries to inject some new life into what's really a very stale formula.
Lifting its storyline wholesale from "Fatal Attraction", this is a plodding teen remake that's so mechanical you can smell the grease on the plot twists.
Although director John Polson handles the material with thorough professionalism - introducing some disturbingly unexpected jump cuts and a creepy soundtrack of gathering violins to good effect - the film's never much more than the sum of its second-hand parts, a fault that not even its enthusiastic leads can overcome.
Squandering every opportunity to flesh-out the film's underlying tensions (the class differences between cello-playing rich-girl Madison and dowdy waitress Amy seem to have been thrown in as an after-thought), "Swimfan" dives headfirst into the deep end of sexual obsession and drowns all subtlety in the process.
And just like "Fatal Attraction", the underlying message here is that it's fine for guys to have affairs - just as long as it's not with bunny boilers. Should Hollywood really be teaching that kind of message to 12-year-old cinema-goers?