The studios wanted Matthew McConaughey, but Cameron insisted on Leonardo DiCaprio.


Before announcing development of this film, director James Cameron shot footage of icebergs off Nova Scotia under the pretence of making a film called "Planet Ice."


When James 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 (1995). 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, James Cameron had a 1/33 scale 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. However, these rehearsals proved largely futile.