Facts about the film

Before announcing development of this film, director James Cameron shot footage of icebergs off Nova Scotia under the pretense of making a film called "Planet Ice."
The name of the character Caledon Hockley derives from two small towns (Caledon and Hockley) near Orangeville, Ontario, Canada, where Cameron's aunt and uncle live.
When Cameron decided to include real footage of the Titanic's remains on the seabed, he did not want to simply shoot from inside a submersible, as had been done for the IMAX documentary Titanica (1992). To allow filming from outside the sub, Cameron's brother Mike Cameron and Panavision developed a deep-sea camera system capable of withstanding the 400 atmospheres of pressure at that depth.
The deep-sea camera held only 12 minutes' worth of film, but each dive took many hours. To make the best use of his resources, Cameron had a model of the wreck constructed and used it to rehearse each dive. The Russian sub operators would walk around the model ship holding model subs in their hands as Cameron explained the shots he wanted.
A total of 12 dives were necessary. On the last two dives, shots were taken by sending a remotely operated vehicle into the wreck; Cameron had intended using this device only as a prop.
Rose, in her old age, owns a Pomeranian. A Pomeranian was one of only three dogs known to have survived the disaster. As the real ship sank, a passenger freed dogs from their kennels, and a survivor later recalled a French bulldog swimming in the ocean. Cameron filmed scenes portraying the doomed animals but cut them.
The studios wanted Matthew McConaughey, but Cameron insisted on Leonardo DiCaprio.
Many of the paintings in the movie are authentic, such as Pablo Picasso's "The Guitar Player" flown in from the Musée national d'Art Moderne, Centre Georges Pompidou, Paris. Most of the decor on the ship - from the carpet to the chandeliers - was reconstructed by, or under the supervision of, the original companies which furnished the Titanic.
A 90% scale model of one half of the Titanic was constructed on a beach in Mexico. In the scenes portraying the ship at the Southampton dock, all shots were reversed to give the appearance of the port side of the ship, as it was actually docked in 1912. This required the painstaking construction of reversed costumes and signage to complete the illusion, which was achieved by reversing the image in post-production.
So many lights were required that cinematographer Russell Carpenter commented: "And you walk inside, and 70 miles of one kind of cable and 70 miles of another kind all add up to this Terry Gilliam vision of the telephone company of the 1950s."
On the final night of shooting in Nova Scotia, one or more pranksters mixed PCP (angel dust) into the clam chowder served to the cast and crew. 80 people were taken ill, many hospitalized with hallucinations. Bill Paxton felt listless for two weeks after the incident.
When Jack (Leonardo DiCaprio) is preparing to draw Rose, he tells her to "Lie on that bed, uh I mean couch." The line was scripted "Lie on that couch", but DiCaprio made an honest mistake and Cameron liked it so much he kept it in.
Jack's sketch of Rose wearing the necklace was drawn by Cameron; it's his hands we see drawing the picture. Cameron also drew all the other pictures in Jack's sketchbook. See also the goofs entry.
David Warner (I) appeared in two previous films in which the Titanic sinks: S.O.S. Titanic (1979) (TV) and Time Bandits (1980) (However, he was not on board the ship in the latter, where the reference to the Titanic was minor.)
The rooms that Caledon Hockley, Rose DeWitt Bukater, and Ruth DeWitt Bukater occupied (B52, B54, and B56) were actual rooms on the real Titanic, booked to Bruce Ismay.
The engine room scenes were partially filmed aboard the WWII ship SS Jeremiah O'Brien. Smaller railings and catwalks were installed to make the engines appear bigger.
The completed film ignores the freighter Californian, which had stopped for the night due to the ice hazard and was within sight of the Titanic throughout the sinking. (The Titanic's radio operator was too busy sending passenger messages to listen to the Californian's warning of ice, then the Californian's radio was turned off overnight, and its captain failed to act on the distress rockets.) An early version of the script included a scene on the Californian, but Cameron cut out the subplot after filming it to shorten running time. Actors in the scene on the Californian included Adam Barker (II) as radio operator Cyril Evans.
The most expensive first-class suite on the Titanic cost $4,350, the equivalent of about $75,000 today.
In real life there was concern that the davits might not be strong enough to lower the boats fully loaded, although they had in fact been tested under such a weight. The davits in the film, which can be seen flexing under the weight, were made by the same company as the real-life ones.
Cameron forfeited his $8 million director's salary and his percentage of the gross when the studio became concerned at how much over budget the movie was running.
When Rose is afloat on the wood looking up at the stars, there is a vague image of the necklace. It is outlined by brighter stars shaping the heart loosely, and a few bright stars shaping the chain.
After deciding on the lead characters' names, Cameron discovered that one member of Titanic's engineering crew killed in the sinking was "J Dawson". (James) Dawson was a trimmer: someone who stows the coal and cargo on board.
Directors Trademark (James Cameron): [feet]: The shoe at the beginning, Rose's feet while climbing the rail, Jack's feet when taking off his shoes, Rose's and Jack's feet while dancing.
Directors Trademark (James Cameron): [nice cut]: Several dissolves between the Titanic on the seabed to the Titanic of the past, and the dissolve from the young to the old Rose.