The film tells the story of the exploratory spirit Tammy Oldham (Shailen Woodley) and her fiance Richard Sharp (Sam Claffrin), who set sail across the Pacific Ocean from Tahiti with blue skies and blue skies, in order to complete the adventurous sailing journey of their dreams. There were unforeseen circumstances, but the two were suddenly attacked by a Category 4 hurricane named "Raymond", which ranks among the top ten in the world in intensity during the voyage. After the storm, Tammy, who was leaning on driftwood, woke up and found that the sail boat had been destroyed and dilapidated. What was even more unfortunate was that her beloved man Richard was dying due to serious injuries. Tammy lingered around hope and despair, and then With Richard's encouragement, she firmly kindled the hope of survival, and burst out with willpower and courage in desperate situations, struggling to survive in the endless sea...