Starring Kate Winslet, Leonardo DiCaprio, Billy Zane • Directed by James Cameron   • Age restriction: 13LNV • Releases 5 April

Nearly fifteen years after Titanic sailed on to the big screen in a film that won 11 Academy Awards and made superstars of Kate Winslet and Leonardo DiCaprio, James Cameron's epic returns to cinemas – this time in 3D.

It's the exact same film – all three-and-a-quarter hours of running time – but this time, exquisitely rendered in the format that Cameron made famous with his last film, Avatar.

Cameron has been critical of converting new films as part of the post-production process, rather than filming in 3D – but has supported the conversion for older "library titles" – including Jaws, ET, Indiana Jones... And Titanic.

His disdain for trying to "shoehorn" films into 3D – he famously cited Clash of the Titans as an example of bad 3D – means that he was going to throw everything he could at ensuring Titanic lived up to his famously high standards. And 60 weeks and a reported $18-million later, that it does.

The success of Titanic's 3D lies in its subtlety, making this great film even more immersive and sweeping than it was fifteen years ago. From the first, goosebump-inducing shot of the wreck of the Titanic emerging out of the gloom to the now-iconic "I'm flying!" and, of course, the still-incredible scenes of the Titanic's sinking; every shot has been painstakingly rendered to maximise effectiveness. The ship seems even bigger, the corridors and staircase and state rooms even more vast than it all did the first time round. And the sinking – well, I physically winced watching passengers fall off the top of the doomed, now-vertical liner.

I've seen Titanic more times than I can remember – though not for a few years – and it regularly ranks near the top of my favourite films. And while some of the computer-generated effects may seem dated, it is still a technical triumph of filmmaking – incredible cinematography, costume and set design, scoring, editing and sound.

Cameron has revealed that before starting work on converting Titanic, they went back to "clean up" the film – and it's pristine. It's been brightened up, it seems, to account for the inevitable dullness that comes with viewing the film through 3D glasses (oh, for auto-stereoscopic films and the end of those horrid glasses!). And where modern films – with quick-fire cutaways and rapid shots – inevitably blur in 3D; Cameron's exquisite classic shots, lingering close-ups and slow, sweeping landscapes translate incredibly, adding a subtle depth to the film to enhance the immersive experience – which in my mind is what 3D should be used for, not throwing vases at your audience.

Titanic itself still holds such power. Winslet and DiCaprio – so young in this film – have an incredible chemistry that is often lacking in more-modern romances, and their pairing has regularly been cited as one of the reasons for the film's success. DiCaprio, so young and so good-looking, is possessed with a youthful, uncontrollable exuberance in wandering artist Jack that he has trimmed in his quest to become a serious actor – and one of the greats of the current generation. And Winslet, nominated for an Oscar for her role as the fiery Rose, is full of the promise of her glittering career.

Kathy Bates as Molly Brown, Frances Fisher as Rose's mother Ruth Dewitt Bukater and Victor Garber as the ship's builder Thomas Andrews provided strong and deep supporting turns, while Billy Zane is still deliciously clichéd as the moustache-twirling villain and Rose's loathsome fiancé Cal. And the late Gloria Stuart as Old Rose still is the link that holds the film together, carrying the past and the present on her shoulders.

It has become fashionable in recent years to hate Titanic on principle, mocking everything from the famous "I'm the king of the world!" scene to "I'll never let go, Jack". Yes, the dialogue is over-stuffed and sometimes cringe-worthy – and yes, there was a reason that Cameron's original script was overlooked entirely by the Academy.

But it's the feelings that Titanic and its two leads evoke, rather than the words that they speak, that make this film a classic of the modern era. And the film's 3D outing, on the anniverary of the centenary of Titanic's sinking, is the film's crowning moment.

Love it or hate it, whatever your feeling on the film, it's hard to deny that Titanic is Cameron's masterpiece.