Revealing mistake: Just after Rose spits in Cal's face and runs off to find Jack, the camera goes into the water to show Jack through one of the portholes. In the external shot, it shows that the porthole is a good distance under the water. However, just as Jack says "Hello? Help me" you can see the water dip below the top of the pothole a number of times as it sloshes about.
Continuity mistake: When Jack looks through the porthole (which is full submerged underwater) while cuffed, he looks over his left shoulder which is facing the hull of the ship. He then turns his head which cuts to him inside the room, his left shoulder is now facing away from the hull of the ship, towards the door. The shot of him looking through the porthole is possibly a reversed shot.
Continuity mistake: When Jack is manacled in the master at arms' cabin as it floods, the drawers from the left-hand side of the desk behind him are floating around in the water, then for a short shot are back in the desk and then floating around in the water again.
Continuity mistake: When Rose is hanging off the back of ship she first isn't holding the train of her gown then suddenly she is.
Factual error: In the seen after the preacher finishes his dialogue; it shows the woman floating in the first class lounge with which is completely under water. But about a minute or so later after it shows the maid slide down the deck, the part of lounge that was supposed to be flooded is still above water. The lounge in just a bit forward of the 3rd funnel on A Deck which wasn't submerged until after the break up in the film. The light fixture is one deck down aft of the compass tower between funnel 2 and 3.
Factual error: When Rose's mother is having tea, all the women are wearing gloves as they have tea. This would never have happened as Edwardian ladies always removed their gloves and placed them in their laps under their napkins when they sat at a table, before eating or drinking anything so as not to soil them.
Continuity mistake: After Old Rose watches the taped images of the sunken Titanic, Lizzy puts her hand on her shoulder. Then she takes it off and moves away. When the angle changes her hand is still on Rose.
Continuity mistake: When old Rose grabs the dragonfly jewel she places her left finger under the broken wing. When the angle changes her finger is away and she is repeating the previous movement.
Other mistake: In the scene where Rose is sitting in front of her vanity mirror after Jack saves her life, Cal bestows upon her the 16-carat Heart of the Ocean necklace. He drapes the necklace around her neck but never actually fastens it (the camera's on him the whole time), yet it stays in place even as Rose touches the diamond and runs her fingers across the chain. A 16-carat diamond would slide right off someone's neck if it were not properly fastened.
Suggested correction: It's actually 56 carats, and if you watch it again, he keeps his hand on the back of her neck over the clasp. He is the one keeping it in place.
