A model of the Titanic was built at a cost of $350,000. When it was finished, it was discovered that it was too big for the tank in which it was to be filmed. An additional, bigger tank had to be built, at a cost of $6 million.
Stanley Kramer was hired to direct, but quit after two weeks due to "creative differences".
The Titanic model used for filming was on display at Anchor Bay, Malta, in a building close to the set used for the town of Sweethaven in the film Popeye (1980). It is now next to the deep water tank purposely built for it at the Rinella studios in Malta. The model was sadly damaged beyond repair in a storm that hit the Island in 2003.
Steve McQueen was offered the lead role in the film. However, he felt the script was flat and turned down the offer.
Author Clive Cussler so hated this movie that he refused to allow any of the film rights for his other Dirk Pitt novels to be sold. He finally relented after over 20 years - signing over the rights for three of the novels. The first to be filmed was Sahara (2005), but once again Cussler was unhappy with the script and is involved in ongoing litigation with the producers.
Cameo: [Clive Cussler] reporter during a press conference
M. Emmet Walsh's character was originally Dirk Pitt's literary sidekick Al Giordino, and was referred to as Giordino in some publicity material. He was also killed off towards the end of at least one early draft of the script.
When discussing the film's cost, producer Lew Grade famously said that it would have been cheaper to lower the Atlantic.
In the scene where the camera pans across the Titanic immediately after she surfaces, about midway along the hull, look for a very tiny bit of movement in the lower part of the picture. As a gag, the spfx guys rigged up a little prop consisting of two tiny scale figures working a hand pump.