In 1996, Brock Lovett (Bill Paxton) and his team of "Treasure Hunters/Grave Robbers" come to the shipwreck of the R.M.S. Titanic, searching for the priceless diamond known as "The Heart of the Ocean". Lovett and his team send a robot submersible into the wreck. The robot goes into a tattered bedroom. Lewis Bodine (Lewis Abernathy), a co-worker and friend of Lovett, uses the mechanical arms of the sub to move over furniture to find a safe, containing their prize.
They come back onto the surface to a boat where the rest of the crew is celebrating the find of the safe. Brock feels around inside the safe for what he is looking for. He finds paper and a sketchbook, nothing else. Back inside of the boat, Lovett's team is analyzing the papers that were found inside the sketchbook. One in particular is a nude portrait of a woman lying on a couch wearing a necklace. Brock realizes that the necklace is the Heart of the Ocean. He checks the date, April 14, 1912 (signed J.D.), the day of the Titanic's sinking. He realizes whoever the woman in the picture is must know where the diamond is, but unfortunately has no idea who she is or whether or not she's dead or alive.
Meanwhile, in her quiet home, 101-year-old Rose Calvert (Gloria Stuart) is making pottery as her granddaughter Lizzie (Suzy Amis) casually goes about the house, feeding the dogs. The T.V. is heard in the background. It is on the news station and what catches Rose's attention at first is a line said by someone mentioning the Titanic. It shows Brock Lovett as he discusses what he is doing. Rose gets up and listens in. Brock speaks of the care his experts on the ship are taking with what they found in the wreck. They show the picture of the woman and Rose stares in amazement, nearly speechless. Back on the ship, Lovett is helping to launch the submarine into the water once again when he is interrupted by his comrade, Bobby Buell (Nicholas Cascone). Bobby claims that there is a call waiting for him that he will want to take. Brock reluctantly gets on the phone and speaks to the elderly Rose. The first thing Rose has to say is "I was just wondering if you had found The Heart of the Ocean yet, Mr. Lovett?" and he is hooked instantly. He asks whether or not Rose knows who the woman in the picture is and Rose certainly does; she tells him it is her.
The next thing seen is Rose and Lizzie being shipped by a helicopter over to Lovett's boat. Onboard, Brock is being briefed by Lewis on Rose's background. He believes Rose is nothing but a fake, seeking publicity. He describes how the woman Rose claims to be, Rose Dewitt Bukater, died on the Titanic when she was 17, according to records. He has done a background check on the old woman all the way back to the 1920's when she had worked as an actress in New York. Back then her name had been Rose Dawson, not Dewitt Bukater. She later married a man named Michael Calvert and they moved to Cedar Rapids, Iowa where they had kids. But there is no history or record of her before 1920. Still, Brock believes Rose may be who she says. Rose and Lizzie are then seen exiting the helicopter with their luggage. Rose and Lizzie get set up in their quarters, arranging Rose's pictures beside the bed. Brock asks Rose if she needs anything and her only desire is to see her drawing. Rose goes into the room where everything recovered from the wreck is and sees the portrait in a tank of clear water and closes her eyes, remembering the day it was sketched. We see the hands of a youthful man sketching the drawing for the first time. We then see his blue eyes look up, wisps of blonde hair in his vision... Rose opens her eyes and comes back to reality.