Heart of the Ocean (symbol)
The Heart of the Ocean is a symbol of Rose's heart and her love for Jack, as conveyed by her line, "A woman's heart is a deep ocean of secrets." For Rose, the diamond's value is not determined by its magnificent size, but rather by the context and meaning it holds for her as a memento of her time with Jack. This is why Rose decides to drop the jewel back into the North Atlantic, rather than turn it over to treasure hunters. By doing so, she symbolically reunites with Jack, and dreams that night that she is back with him aboard the Titanic.
Titanic (symbol)
The Titanic, as a spectacular feat of shipbuilding, is a symbol of human pride and modernity. The ship holds special appeal for the film's male characters, such a J. Bruce Ismay and Cal Hockley, who are obsessed with its sheer size and luxurious amenities. By fixating arrogantly on the feat of the ship's construction, the men ignore its fallibility, and discount the possibility that it could ever be sunk. The ship means different things for different people—for Rose, for instance, it is a "slave ship, taking [her] back to America in chains." For Jack, it is a portal to a new and exciting world. All of its passengers are eventually faced with the consequences of the ship's collision with an iceberg, which is the result of the arrogant overconfidence of the leadership of the White Star Line.
Romeo and Juliet (allegory)
James Cameron initially pitched the film as "Romeo and Juliet on the Titanic." Instead of staging a rivalry between two warring families, as was the case in Shakespeare's play, Cameron instead renders a "star-crossed" romance between an aristocratic girl and a penniless boy. The passionate intensity with which Jack and Rose fall in love, as well as the staggering obstacles that prevent them from being together, help turn the film into an allegorical re-telling of Romeo and Juliet. The undying intensity of their romance is best summed up by the line, "You jump, I jump, right?" uttered by both Jack and Rose at various points in the film.
The band (symbol)
The band continuing to play while the ship sinks is a powerful symbol that conveys the resilience of the human spirit in the face of certain tragedy. The Titanic's sinking is an event that reveals the character and integrity of its passengers, revealing some to be courageous, some to be cowardly, and so on. The band's decision to keep playing—even returning after the bandleader gives them permission to leave—is a testament to the grace with which they confront the tragedy. The anecdote of the band playing until the last second now circulates widely in popular culture, and was the basis for the title of Randy Shilts's 1987 AIDS memoir And the Band Played On.
The shipwreck (symbol)
After opening with sepia-toned glimpses of the Titanic departing from Southampton, the film shifts to footage of the actual wreckage that now lies at the bottom of the North Atlantic. The shipwreck symbolizes the passage of time, the loss of life, and the receding of the event from the public eye. Brock Lovett struggles to relate to the human element of the tragedy, given that he only has access to the crumbling, seaweed-ridden hull in which he hopes to find the Heart of the Ocean. It is only when Rose's memories re-animate the ship in his mind, and the minds of viewers, that he is able to finally absorb the emotional impact of the disaster.
