The 30-mile stretch of ocean between the Farallon Islands and San Francisco’s Golden Gate Bridge is considered to be one of the toughest swims in the world—a grueling trek through frigid, sharkinfested waters completed previously only by two men. That's all the motivation New Zealand-native marathon swimmer Kim Chambers needs to attempt the impossible. Chronicling her incredible story (remarkably she began swimming only as an adult), Kim Swims is a moving look into a fiercely determined spirit and the physically (and cinematically) awe-inspiring feat she attempts.