TITANIC was never meant to be a kid's movie, hence the PG-13 rating. I admit that it is a bit edgier than other PG-13 movies, but it never really deserves an R rating. I am very concerned about what I expose my children to, yet even I was surprised at a lot of reviews on this page that described the content in the film as "horrifying" and shocking.
The movie does have a fair bit of language in it, but considering the over three hour running time, profanity is actually quite sparse. There is one "f" word, but other than that, there is much less profanity in this film than in many other PG-13 movies, especially when given the long running time of the movie. There is brief nudity, but I didn't find it to be extremely offensive. Considering the fashions in which most nudity is portrayed in films today, this scene was very chaste and brief. You see the woman's breasts and the top of her butt for probably ten seconds max. It isn't presented in a lewd or overtly sexual manner, and while obviously it isn't a wise choice for the lead character to make, it certainly never encourages teen girls to do anything of the kind. The love scene is even shorter than the first scene, and shows absolutely nothing. While kids should understand that this is poor behavior, the film never promotes it. The main aspect of the film parents should be wary about is the harrowing violence. This is one of the most difficult movies I've ever seen, as an adult even. Mass panic is shown as people drown and plunge to their deaths as the ship sinks. Mothers and daughters are shown crying out for each other as they slowly perish, and children are lost in the midst of the hysteria. People commit suicide, and almost all of the main characters perish. For an extended period of time, we see frozen bodies of victims in the water, including those of infants. I'm not sure about the rest of you, but I would much rather have my child see some brief, chaste nudity than be exposed to this potentially traumatizing violence. For that reason, I recommend the film for ages 15+ for kids to watch alone, perhaps younger if accompanied by a parent.