THE Belfast shipbuilders of the Titanic are "unsung heroes" who made it possible for many of the passengers to escape, film director James Cameron said.
The maker of the Oscar-winning movie was in the city to launch a new exhibition on the vessel at the Titanic Belfast visitor centre.
He said the designers of the ship worked as it sank to stop it from rolling over - allowing lifeboats to be lowered to evacuate people.
Mr Cameron said: "I believe firmly that they are the unsung heroes of Titanic, that kept that ship upright, the stately image that we all think of when we think of Titanic sinking.
"It is important for us to continue to look back at history.
"There are still lessons to be learned, there were heroes on board the ship that we did not even realise how important they were... and they were Belfast men."
Cameron's film Titanic won 11 Oscars after its original release in 1997. A 3D version was produced to coincide with the centenary of the vessel's sinking earlier this year.
Cameron and producer Jon Landau opened the first exhibit dedicated to the film at the world's largest Titanic museum - Titanic Belfast. The display features props and costumes highlighted in some of the most memorable scenes from the film.
There are some items from Cameron's personal collection including the ship's wheel and other technical equipment. Costumes have been borrowed from 20th Century Fox, including the originals worn by the film's stars Leonardo DiCaprio and Kate Winslet in their final scenes.
The newly opened museum is 100 yards from where Titanic's hull was launched and beside it is the drawing office where she was designed. She set sail from the city's River Lagan.
Shortly before midnight on April 14 1912, the passenger liner struck an iceberg on its way from Southampton to New York. It sank less than three hours later, killing 1,517 people.
Mr Cameron said it was human intervention which kept it from rolling, as engineers from Harland and Wolff shipbuilders used pumps to move water around and prevent the vessel from tipping over on its side.
The Titanic movie, which took two years to film, saw Winslet play upper class socialite Rose DeWitt Bukater opposite DiCaprio's third class passenger Jack Dawson.
Until the release of Avatar in 2009 - also directed by Cameron - Titanic was the most successful movie ever, with global takings of 1.843 billion dollars (£1.14 billion).
Cameron was in Belfast with producer Jon Landau.
He said his favourite scene was Winslet and DiCaprio kissing as the sun set.
He recalled the crew tripping over each other to be ready as they realised the right moment had arrived, with Winslet running and people following behind, fixing her dress.
"One take was completely out of focus and one was partially out of focus and that is the one in the film," he said.
"It was one of those great serendipitous moments where everything came together."
He said the energy of the crew and all the planning and rehearsing had come together and that was why he liked the scene, quite apart from the emotion of it.
"It all happened; that is the magic of movie-making," he added.
Cameron has made several dives to the North Atlantic seabed to view the Titanic, piloting a small vehicle inside the wreck and exploring its interior.
He said: "Titanic still exists. It is gone from our surface world, but it still exists as a time capsule down there on the sea floor."
He paid tribute to those behind Titanic Belfast.
"It is a magnificent, dramatic building, the largest Titanic exhibition in the world, not only how it (shows) the history and legacy of Titanic itself and Belfast's part in the creation of the ship, but it is also such a celebration of Belfast's contribution to the building of so many fine ships, hundreds of ships, at a point where it was coming into its own as a major industrial power. It is a celebration of the city and the people."
He said although the film did not focus on the making of the vessel there were traditional bodhran drums representing Ireland used in the soundtrack.
"We wanted to get that bit of the soul of the ship, which is an Irish soul," he added.
"That helps pull on the heartstrings and makes the emotion of that tragic story more powerful for the Irish."
Producer Landau said 3D technology allows the audience "in the room" with the cast during the more intimate moments of the film.
The setting for the film was modelled on a real engine from the Titanic, and everything was built to scale from it.
Chief executive of Titanic Belfast, Tim Husbands, said he was delighted to welcome Cameron and Landau to the building.
"This is where the story was given shape, the authentic site where dreams were cast and promises were made and a story which was to become so iconic it captured and fired the imagination of both film-maker and adventurers alike," he said.