[Rose shows Jack her engagement ring]
Jack: God! Look at that thing! You would've gone straight to the bottom.

[Trying to stop Rose from committing suicide by jumping from the ship]
Jack: Which is why I'm not really looking forward to jumping in there after you. But like I said, I don't have a choice. I guess I'm kinda hoping you'll come back over the rail and get me off the hook here.
Rose: You're crazy!
Jack: That's what everybody says, but with all due respect miss, I'm not the one hanging off the back of a ship here.

(when jack met rose)
Jack: Don't do it!
Rose: Stay back! Don't come any closer!
Jack: Come on, just give me your hand. I'll pull you back over.
Rose: No, stay where you are! I mean it! I'll let go!
Jack: No, you won't.
Rose: What do you mean, "No I won't"? Don't presume to tell me what I will and will not do, you don't know me!
Jack: Well, you would've done it already.
Rose: You're distracting me! Go away!
Jack: I can't. I'm involved now. If you let go, I'm gonna have to jump in there after you.
Rose: Don't be absurd. You'd be killed! The fall alone would kill you.
Jack: It would hurt. I'm not saying it wouldn't. To tell you the truth I'm a lot more concerned about that water being so cold.
Rose: How cold?
Jack: Freezing. Maybe a couple degrees over. You ever been to Wisconsin? They have some of the coldest winters around. I grew up there, near Chippewa Falls. Me and my dad would go ice fishing. Ice fishing is where you...
Rose: I know what ice fishing is!
Jack: Sorry. You just seemed like kind of an indoor girl. Anyway, I fell through some thin ice and I'm telling ya, water that cold, like right down there, it hits you like a thousand knives stabbing you all over your body. You can't breathe. You can't think. At least not about anything but the pain. Which is why I'm not looking' forward to jumping in there after you. But like I said, I don't have a choice. I guess I'm kinda hoping you'll come back over the railing and get me off the hook.
Rose: You're crazy...
Jack: That's what everybody says. But with all due respect miss, I'm not the one hanging over the back of a ship here. Give me your hand. You don't want to do this. I'm Jack Dawson.
Rose: Rose De Witt Bukater.
Jack: I'm gonna have to get you to write that down.