James Cameron has already answered to astrophysicist Neil deGrasse Tyson by changing the star field glimpsed in Titanic to make it more accurate, but so far he's been reluctant to address another, more oft-heard complaint about scientific exactitude demanded by viewers who don't know how to feel, apparently. We speak, of course, of the "They Both Could Have Fit" argument that recently became a viral hit, demonstrating that Rose and Jack could have easily shared that same driftwood, playing cards and copulating and gradually realizing that they have little in common beyond lust and circumstance, until the lifeboats finally arrived. But as it turns out, Cameron did see your little pseudo-scientific "debunking," and he's got an answer—and what's more, he plans to appear on an episode of Discovery's MythBusters to prove he's in the right once and for all. Here's a taste:
Actually, it's not a question of room, it's a question of buoyancy," Cameron explains. "When Jack puts Rose on the raft, then he tries to get on the raft. He's not an idiot, he doesn't want to die. And the raft sinks and kind of flips. So it's clear that there's only enough buoyancy available for one person. So he makes a decision to let her be that person instead of taking them both down.
If you know anything about hypothermia, the more you're submerged —and she's completely out of the water on the raft, and it's only about that far above the surface. If they he had gotten on with her they both would have been half in and half out of the water, even if they could balance on it, and they would have both died.
Indeed, do not challenge James Cameron about water. James Cameron owns the water.