Film: I've got that sinking feeling

There are any number of reasons why the SS Titanic ended its maiden voyage imbedded in the ocean floor in the early hours of 15 April 1912 - poor visibility, a negligent captain, a big hunk of ice. To this list the film-maker James Cameron adds one more contributing factor to lessen the burden of responsibility on that iceberg: a pair of bored officers distracted from their vigil at the warning bell by the sight of a couple canoodling on the deck. This is actually one of the more plausible details in the thoroughly loopy new film Titanic, if only because it obeys the cardinal rule of the disaster movie, which decrees that any and all catastrophes shall occur in exact correlation to the effrontery of the characters involved. You play with fire and you get burnt. Or drowned.

The voyeuristic sailors aren't to blame for the corpses littering the ocean. It's the fault of those young lovers - Rose (Kate Winslet), who is poised to marry into obscene wealth but chooses instead to desert her fiance in favour of Jack (Leonardo DiCaprio), a scruffy ragamuffin from that overpopulated district, the Wrong Side of the Tracks. The naivety of the movie's characterisation is almost charming. The rich are all prissy and repressed, while the folk in third class may be as grubby as new spuds, but boy do they know how to party! There's always an arm-wrestling tournament or an Irish jig in full swing, and if that doesn't warm your cockles, you could just sit and marvel at the nobility of the poor.

It's disappointing that the class distinctions, which become more pronounced during the scramble for lifeboats, are played out with an eye to sentimentality rather than poignancy. For all the shots of the beleaguered poor straining against the iron shutters which imprison them in the ship's belly, there is no image here as fragile or unforced as the moment in A Night to Remember when the third-class passengers stumble into the deserted first-class dining room and momentarily pause in their panic to suppress gasps of wonder and envy at the luxury that will soon be swallowed by the ocean. The only satisfying dramatic friction between the classes comes when Rose proudly denounces her upbringing until she finds herself in need of its benefits. Feigning offence at Jack's impudence, she huffs "This is MY part of the ship!"

Their rather touching romance is a violation of social etiquette, and the symbolic catalyst for the disaster which follows - why else would the Titanic's collision be immediately preceded by the scene where Rose and Jack make love for the first time?

It's one thing for Cameron to remind us that many people felt the Titanic's ostentatious grandeur to be an affront to God. But when he speculates that this ship was doomed because a couple of teenagers dared to cross the class divide, he's promoting a new kind of tastelessness. The suggestion that over 1,500 real people died as a sacrifice to the love of two fictional characters doesn't make you swoon, it makes you gag. If Cameron is suffering from a God complex, then that's between him and his analyst - it's not a delusion which should be assuaged using millions of dollars and a movie camera.

Even taking into account the fact that we all know how Titanic will end, Cameron still overdoes the wise-ass 1990s perspective; he makes hindsight a hindrance. The early scenes of Titanic are crammed with portentous dialogue. "Somebody's life is about to change!", Jack announces as he lays down the winning hand in a card game which will earn him his ticket across the Atlantic, while Rose's effete fiance Cal (Billy Zane) grunts "Somebody Picasso?", at Rose's recently acquired canvasses. "He won't amount to a thing."

This phony self-righteousness has blinded Cameron to the fact that the early works of Picasso did not disappear with the Titanic - but if you're sacrificing the victims of a factual disaster on the high altar of epic melodrama, then a few Cubist masterpieces are neither here nor there. Despite the numerous etiquette and dialect coaches hired for the production, period accuracy was never going to be the strong point of any film which allows a passenger onboard the Titanic to give the middle-finger salute.

Cameron's indisputable gift is for staging colossal set-pieces bubbling with incidental detail, and the sinking of the Titanic provides him with a delicious opportunity to exploit this talent. Many of the images which are intended to haunt feel strained and stage-managed but the shots of the Titanic standing vertically in the ocean, one end pointing to the stars while the other lurches toward hell, have an appalling splendour. In the film's 1990s prologue, there is a scene where an explorer conducts a computer-simulated breakdown of the Titanic's last hour, which guides us through the escalating stages of decline and lays out a menu of destruction before us. When the lower decks start flooding, your brain automatically recalls that menu, and you start checking off the contents. The upper deck has just splintered. Ah, yes. There'll be some bobbing about on the surface before it sinks, just like the nice fellow said.

When Cameron has to tackle emotional scenes, he is noticeably less assured. The main purpose of the movie's framing device, which shows the elderly Rose (Gloria Stuart) recounting her story to a team of explorers, is to give us an audience-within-the-film. Cameron is the least spontaneous of all modern directors because he has such little faith in simplicity, or in his audience. When the camera pans around the explorers' tear-stained faces at the end, that's the cue for our tears.

But a whole three hours earlier, the picture has already united the past and the present far more poetically, as the 101-year-old Rose comes face to face with a nude portrait of her teenage self, etched by Jack on board the ship and now recovered from the wreckage and duly restored. As Rose stares at the drawing, we see her through its eyes, as though her younger self had encountered her older self, and both incarnations had become paralysed by the epiphany.

`Titanic' goes on general release today.

Edward Seckerson interviews James Horner, composer of the film's original score, on p8