Titanic (1997): Testing the Infamous Door

The “could Jack have fit on the door?” debate has outlived entire film franchises. Cameron’s answer is basically this: “The story requires Jack to die, so that’s that.” But that wasn’t enough. He also described spending about two days in the water with the floating piece of ornate wood, placing people on it, and adjusting buoyancy until it would support exactly one person with enough “freeboard” (meaning the survivor isn’t fully immersed) to plausibly last in near-freezing water until rescue. So yes, that particular door was engineered by Cameron himself to only hold Rose.

Avatar: The Way of Water (2022): They Built a Tank That Was Basically a Controlled Ocean

Making Avatar: The Way of Water meant Cameron couldn’t fake it with a pool and SFX magic. The production built an enormous custom tank designed to behave like a controllable ocean, complete with wave and current machines for action conditions. They also surrounded the setup with performance-capture cameras and additional monitoring cameras for safety. And, in classic Cameronian fashion, the process has been described as pushing the system until something breaks, fixing what broke, then pushing even further. This does explain why those water sequences feel less like kiddie-pool fun and more like you’re watching a real motion of the ocean.