She Ditched The Wet Suit
Because they had freezing water on the set, actors had to wear wet suits. However, Kate Winslet refused to put it on. She was worried that doing so would hold her back from performing to the best of her capabilities. Unfortunately, she ended up suffering for it. You see, she wound up getting pneumonia!
Down To The Second
In an effort to make the movie as authentic as they could, James Cameron made sure that scenes took the same amount of time that they did in real life. If you need an example, you can just look at the collision of the ship and the iceberg. It took 37 seconds in real life, which is also the case for the film.