The movie begins in 1820, where the young whaler Owen Chase (Tom Holland) dreams of becoming a great sailor. He joins the whaleship Essex, captained by George Pollard (Ben Walker), and first mate Thomas Nickerson (Brendan Gleeson). On their voyage, they encounter a massive sperm whale that attacks and sinks their ship. The crew is forced to survive on a lifeboat with limited supplies, facing extreme hardships and struggles.