One of the first screenplays I ever worked on was an early version of this slasher directed by Boris von Sychowski. The movie's two main distinctive features are a particular nasty death involving a waterslide and machete, and a then-unknown James McAvoy (of The Last King of Scotland [2006 / trailer] and Wanted [2008 / trailer]) as one of the body count. The fact that the cast was international was one of the reasons an English-language script was needed.
The screenplay translation job actually belonged to the talented translator Finbarr Morrin, but for a variety of reasons he pulled me in to help. We were allowed to suggest alternative dialogue, a rarity when it comes to screenplay translating. And though the final script filmed obviously went through many more hands (a whole secondary subplot was later added), when I finally caught Swimming Pool on DVD I recognized at least one of my lines: a "joke" said in passing that was so timely — it was tailored around the then-current pop hit by the Bloodhound Gang, The Bad Touch, and the lyric "You and me baby ain't nothin' but mammals; so let's do it like they do on the Discovery Channel" — that it's incomprehensible to today's audience.
Remember the song? Refresh your memory with the video below.
Bloodhound Gang, The Bad Touch: