In the climactic scene of the film, Jack and Rose are left floundering in the freezing waters of the Atlantic. As hundreds of people panic and drown around them, the pair find a door from the ship floating in the water. Jack helps Rose onto it, but the door won’t hold him too. Exposed to the ice cold, he shortly afterwards dies of hypothermia, while Rose survives thanks to his sacrifice.
Jack’s death scene has been the topic of debate for a long time. Even Mythbusters took it on in 2012. It concluded in the end that Jack could have gotten onto the door and survived, but only if he’d tied Rose’s life jacket underneath it first. Surely he’d never have thought of that, in the middle of such a terrifying scenario? Nevertheless, the Mythbusters deemed it “plausible” that both lovers could have made it out of the water.