Clocks
Clocks and clock imagery are pervasive in the film. Rose meets Jack by the ornate clock in the first-class lobby for dinner, and later imagines him there in her dreams. Thomas Andrews spends his final minutes on the ship staring at a clock above the mantel of the fireplace in the first-class dining quarters. Clocks symbolize the themes of time and memory that influence the film's representation of an eighty-seven-year-old epic romance.
Water
The ocean, and water imagery in general, represents the turbulent and unstoppable forces of nature that sink the Titanic and reduce mankind to a humbled state. J. Bruce Ismay refuses to believe that the Titanic will sink below the water until Thomas Andrews tells him, "She's made of iron, sir. I assure you she can." As the minutes of the second half of the film wear on, the water continues to gradually rise through D-deck, then C-deck, then the entire ship, before swallowing it entirely.
Fine art
Upon arriving in her cabin, Rose unloads her prodigious art collection, including works by Picasso and Monet. As an admirer of fine art, she lends a critical eye to Jack's drawings, which impress her greatly. Jack and Rose bond over Monet's use of color in his lily pad paintings, and Rose asks Jack to draw her "like one of his French girls." The discovery of this drawing, in turn, is what prompts Rose to contact Brock Lovett, and without it he would never hear her story.
Flares
In the second half of the film, the Titanic sends up flares to alert nearby vessels of their emergency. When Rose is descending in a lifeboat, she watches the flares explode in the sky behind Jack's face, creating a surreal and sensational image that captures the emotional turbulence she must feel as she is separated from her true love.
Stars
When Jack and Rose sneak into the ship's cargo area, Jack pretends to be a chauffeur and asks Rose where she wants to go, and she says, "The stars." Later, when Rose is struggling to remain conscious while floating on a piece of debris in the middle of the North Atlantic, she gazes up at the starlight. Neil DeGrasse Tyson famously informed James Cameron that the star pattern she sees was not scientifically accurate, prompting Cameron to change the shot of the stars that Rose sees in Titanic's 3D rerelease in 2017.
