Underwater, 20th Century Fox Rated PG-13, 95 Minutes Written by: Brian Duffield and Adam Cozad Directed by: William Eubank Starring: Kristen Stewart, TJ Miller, Jessica Henwick, Vincent Cassel, John Gallagher Jr, and Mamoudou Athie Underwater, as the name so generically suggests, takes place under water. Deep underwater. Six miles under water. From the trailer, I…