Five teenagers spend the summer house-sitting for Keanu Reeves and discover more about themselves and love in the process. Los Angeles native Alex Israel’s debut film is a plotless, vapid, and exasperating mess. Trying to think of a way to describe SPF-18 is almost as perplexing as the film itself. There is almost no plot, or at least not one that makes an ounce of sense, characters are flat, and their motivations are completely unclear. On the opening of the film, Penny (Carson Meyer) seems borderline obsessed with her ex-flame from high school Johnny Sanders Jr. (Noah Centineo) and has her sights set on losing her virginity to him this summer. Penny and her cousin Camilla (Bianca A. Santos) join Johnny in Keanu Reeves’ Malibu beach house, where they meet singer Ash (Jackson Baker) who has run away from Tennessee to try and escape his controlling record label and is caught illegally camping on the beach by lifeguard Steve (Sean Russell Herman). The five spend the next few days sur...