Kamurai
Average watch, probably won't watch again, and can't recommend unless you're just into swimming / swimming movies.
I already knew Peyton List could carry a movie, and Olivia Nardini is amazing, but this story carries a level of psychological nuance that I don't think it conveys properly. Partly because it hides the nuance in some of the characters as an unnecessary reveal later on, and partly because they just fail to have the character address it directly.
A lot of the movie is her just being a sullen jerk or an angry jerk, but the movie is fairly enjoyable. I think that is mostly due to the great character work by the cast.
While I don't think this movie is a waste of your time, there are just better things to watch.