Five friends—Nat, her boyfriend Tom, Milly, Tyler, and Greg—are on a wild Spring Break in Mexico, relishing their last night of freedom. While Nat steps out to buy some beers, she encounters a beggar who claims to have been attacked by a great white shark, revealing a gruesome story of survival. When her friends join her, they dismiss the beggar's plight with an air of arrogance, prompting him to caution them, but they ignore his warning.
The following morning, in a bid to recover from their hangovers, they steal some jet skis and venture out into the vast ocean. Amidst their carefree antics, disaster strikes when Nat and Greg's jet ski collides, leaving Greg with a broken leg and one ski sinking beneath the waves. As they scramble to stay afloat on the remaining ski, Nat discovers a series of messages revealing a secret affair between Milly and Tom, leading to a heated confrontation that results in Nat losing Milly’s phone.
As they panic over their increasingly precarious situation, Tyler, being the best swimmer, volunteers to seek help. Just as he sets off, a shadow looms beneath the water—the unmistakable fin of a great white shark. A sudden jolt sends all of them tumbling into the ocean, and in a horrific turn of events, Greg becomes the shark's next meal after a struggle ensues.
Tyler, still hoping for rescue, tries to alert a distant fisherman, but his cries go unheard, culminating in a tragic end as the shark claims him too. Meanwhile, Milly's dwindling hope leads to a desperate conversation with Tom, which only adds to the mounting tension as night falls. When Nat spots a red light in the distance, she thinks she’s found salvation, but instead encounters a gruesomely injured man wearing a life jacket.
With little choice, they ingeniously employ driftwood to create makeshift paddles, and Nat, ever the resourceful one, gives a life jacket to Milly, who cannot swim. Just when they think they might escape, the shark attacks again, targeting Tom this time. In a moment of courage, Nat retaliates by stabbing the shark in the eye, sending it away temporarily. As they realize that their only hope lies in restarting the ski's engine, a calamity ensues when the shark’s relentless attacks scatter them in all directions.
In a frantic series of events, Nat retrieves the life jacket from Milly’s ravaged body, racing against the clock to save her friends. In a heartbreaking choice, she opts to save Tom, while Milly meets a horrifying fate at the jaws of the shark. As Tom grows weaker, Nat musters her strength to repair the engine, narrowly escaping the predator several times.
However, as the engine starts, Tom's decision to draw the shark away leads to a gut-wrenching separation. Nat, faced with the reality of her survival instincts, abandons Tom to his grim fate, racing towards the shore. With one last push against the odds, she crashes onto the beach, leaving behind a trail of heartbreak and horror, yet strikingly, she emerges unscathed—still remarkably pale after enduring two harrowing days without protection under the sun.
