By far the worst [dramatic license] in this movie is the [magic property] that water which is freezing cold outside the ship, causing rapid [hypothermia] and [death], does not act the same way when it is inside the ship.

And just where do they suppose all that water came from?

Somehow this is lost on the moviegoing audience, most of whom have never been in freezing cold water, and probably figure you just get awfully chilly.

Lemme tell you a story: this past [Thanksgiving] our Big Family Gathering/Dinner was held in [Boston], and my cousin lives just outside Boston on a lake in [Natick]. We all grew up [water skiing] (he is extremely serious and has a national ranking now) and he has usually taken the boat out by then for winter, but this year he left it in so we could help out. Somehow one of us gets the idea that we should go for one last post-holiday end-of-the-season [ski]. The air temperature is just above [freezing], so the water temperature is probably just a hair above that. Someone else comments that this is probably very foolish, and then we all agree that [It Must Be Done].

My cousin has lots of cold-weather ski equipment, including "[drysuit|drysuits]", which is essentially a giant watertight rubber [wetsuit], so all that's exposed to the water are your hands, feet and (if you fall) your head. I went for one [loop] of the lake, which felt like 20 minutes but was probably more like 5. It was, as expected, damn cold. But a hell of a lot of fun: as we're doing this we're imagining all the families on the lake having their midday Thanksgiving meal, looking out their window, and wondering who those [idiots] are that are water skiing in late [November].

So here's the thing: when I got back in the boat, after just having my hands and feet exposed for maybe five minutes, I was completely helpless. I couldn't move my [fingers] at all, nor could I really wiggle my [toes] much. Gradually the feeling came back, but it took several minutes of warming up before I had the [dexterity] to put my [socks] back on. And that water was not nearly as cold as, say, the [North Atlantic] at night in [the dead of winter] with [iceberg|big hunks of ice] floating around in it.

So as [Kate Winslet|Kate] and [Leonardo DiCaprio|Leo] go traipsing around waist-deep in [seawater] through the middle third of the film, realize that it is not a question of whether they can make it up to the top, avoid [villain|the bad guy] and get on a [lifeboat], it is more a question of will they be able to move their fingers enough to pick up objects and turn the first [doorknob] they come across, not to mention the fact that they're not wearing drysuits, so their whole body, vital organs included, is affected. The answer is: nope, they would be paralyzed in minutes¹.

But it's a much shorter movie that way.

¹The most insulting part of this is that Leo's character actually explains all of the nasty effects of hypothermia to Kate (and to us in the audience) in the scene where he talks her out of jumping to her death early in the movie. Then they proceed to spend a good half an hour later in the film frolicking around in the water-filled ship as if it were just another day at the pool.

Titanic (idea)