Two members of the swim team included Wentworth Miller (Michael Scofield on Prison Break) and Shane West (Dr. Ray Barnett on ER, although I will always know him as the dude who dated Mandy Moore in A Walk to Remember, don't judge me). Miller gets to act out an "awesome" transformation scene reminiscent of something from Alien or Species. Clearly he's improved his acting skills since the '90s.
Then the principal catches them and is mad at her for injuring a member of the swim team before the very important state championships. (He earlier "suggested" that Willow change the grade of another swim team member so he would still qualify for the team.)
BUFFY: I was not the attacker Principal Snyder, I was the attacked.
PRINCIPAL SNYDER: That's not how it looked from where I'm standing.
CAMERON: I don't know what happened. First she leads me on and then she goes 'schizo' on me.
BUFFY: Lead you on? When did I lead you on?
CAMERON: Come on. ...I mean, look at the way she dresses.
Then later the swim coach also implies that she brought this on herself by saying "Try to dress more appropriately from now on. This isn't a danceclub."
Joss Whedon's shows are always typically more feminist than other average shows created by men, so there are often a lot of moments in BTVS in which Buffy gets treated shitty because she's female and then turns the tables on the guy doing it. It's just interesting though because I specifically remember almost everything about this episode (including what/who the sea monsters really are) except for that scene.
Of course, Whedon makes sure to remind viewers that Buffy can take on any monster (or douchebag). Buffy tries to warn Miller's character Gage that he might be in danger of getting killed by a sea monster but he's annoyed by her "shadowing" him... until he gets attacked by evil-again-for-now Angel. Buffy saves him and then the big tough star athlete asks her to walk him home to protect him. Yep. That's right.
I won't spoil the ending for those of you who haven't seen it, but want to... but basically Buffy saves the day. As usual.