Five months before the hurricane, Tami arrives in Tahiti on board the schooner Sofia and meets Richard Sharp, a British sailor. Richard invites Tami for dinner aboard his boat Mayaluga. During dinner, Richard reveals that he has experienced hallucinations after days at sea.
Shortly before they embark on the ill-fated trip, Tami and Richard bump into Peter and Christine Crompton, owners of the Hazaña, a luxury Trintella 44 yacht. The Cromptons offer Richard $10,000 and a return first-class ticket back to Tahiti to help them sail Hazaña to San Diego, California. Richard accepts the offer, with a condition that Tami comes along. He proposes to Tami with a handmade ring, and she accepts.
Shortly before the hurricane strikes, Tami and Richard receive news of the impending Hurricane Raymond but decide to continue to San Diego anyway. When the storm hits, Tami tries to radio for help, to no avail. The storm alters course and the yacht enters the eye of the storm. Richard and Tami have no choice but to lower the sails to prevent the boat from tipping over. Tami almost falls off the yacht after the boat hits turbulent waves. Richard professes his love for her and demands that she go below where she will be safer. Hazaña is repeatedly flipped after encountering a rogue wave. Tami is thrown about, suffering from her head injury, and Richard is thrown overboard when knocked unconscious by the mast and his safety harness breaks. He slowly sinks into the ocean, while the Hazaña flips and floats back to the surface thereafter.
Tami awakes on the sailing yacht Hazaña after being unconscious. She searches the crippled yacht in hopes of finding her fiancé Richard and realizes he has been swept overboard in a catastrophic hurricane. Tami screams in anguish and it is revealed that she is all alone, with no ships or land in sight.
On the wrecked Hazaña, Tami finds that all electronic devices have been ruined by water damage, preventing her from making distress calls. She spots the lost dinghy with Richard clinging to it and tries to sail the ship towards him to no avail. After falling off the yacht and almost drowning, she has no choice but to make repairs to the ship in order to get it moving. She fashions a makeshift sail using a broken pole and a storm jib (a triangular sail) and a pump to prevent the cabin from flooding. She then makes her way toward Richard. After saving him, Tami realizes that Richard has broken ribs and a shattered right shin. While searching for food supplies, she realizes she has a head injury and stitches the wound with a sail needle and thread.
Tami decides to change course to Hawaii after a delusionary discussion of options with Richard. She sees a tanker heading straight for the Hazaña and fires multiple flares, but the ship sails right past them. Tami wonders if she has been hallucinating. Richard begins to suffer from a high fever; he reminds Tami that a red sky signifies a storm. Tami prepares by creating a makeshift shelter.
Tami realizes the injured Richard on board the Hazaña is nothing but a hallucination, and she surrenders to the reality that Richard has been lost at sea. She sees a Japanese research vessel in the distance and fires two flares. The vessel heads towards Tami, rescuing her. Tami returns to Tahiti after recovering and visits Richard’s boat, bursting into tears after seeing the photos of Richard and herself. She goes to the beach with a frangipani flower, places her engagement ring around the flower, and lets it go in the water.
It is revealed in the credits that Richard Sharp was swept overboard and never found; Tami Oldham was all alone aboard the Hazaña for 41 days and she continues to sail to date.