游泳池

I have seen this movie in German, but the story took place in I think Prague. Because this is the capital of Czech Republic this could be the right movie. It is a horror movie where a group of graduating college students are having an illegal party in a local swimming pool at night. But there is a murderer in the swimming pool, too. This is what I can say without spoiling the fun for other people. I would be pleased if anyone can tell me if this is the movie I am thinking about. I think it is an excellent movie, because you don't know who the murderer is till the end and the murder scenes are quite scary! I don't know how IMDb works, but I would like to see some more information about this movie. I can offer to write something if you want.