In the realms of mega-budget action-adventure directors, few have a reputation to rival James Cameron. From his twin Terminators to the breakneck Aliens sequel, Cameron's movies have long displayed an vivid invention and technical excellence that renders his inauspicious debut (Piranha II) all but forgotten.

Released in late 1989, The Abyss is the story of Deepcore, an experimental deep-sea drilling-rig commandeered by the navy to ostensibly search for survivors aboard a downed nuclear sub. Events both natural and military however conspire to find Deepcore on the edge of an abyssal trench, and crew fighting for its life.

Critics and audiences seemed pretty much in accord over Cameron's $45 million opus - for two hours this was a brilliantly claustrophobic repeat of his Aliens triumph underwater, then in its dying moments it took such a left-twist as to become a water-logged sub-aqua E.T. Ultimately, for all Cameron had striven for realism by shooting for months in huge deep-water tanks with all the resultant stresses and strains on cast and crew, The Abyss was adrift amongst its crippling flaws.

Enter then this, hot on the heels of his celebrated restoration of unseen footage to Aliens, comes 28 extra minutes to his most gruelling picture. The only question remains, was it worth it, or is this, at almost three hours, just more of the same, only on a grander scale?

The answer is both yes and no. The central flaws with The Abyss are destined to remain with it regardless of tinkering. The first three-quarters or so were, and still are, an extraordinary body of work. Cameron's insistence upon shooting underwater means that scenes such as the discovery and exploration of the stranded submarine still retain a palpable energy and tension that is only increased here. And much of the restored footage in this first section is character based, so that with it Cameron emphasises relationships within the rig, and particularly that between separated couple, Ed Harris and Mary Elizabeth Mastrantonio. The inevitability of their reconciliation is always present but is at least now given added poignancy, not least in the lengthy, harrowing scenes of Mastrantonio's 'death' and resuscitation that provide the film with its emotional highlight.

This emphasis of character however also has the same corollary as it did in the original cut: to accentuate the fundamental flaw in the central construction of the film's plotting. Here, as there, Cameron follows what should by rights form the core of the climax with extensive material to flesh out the central, pacifist tenet of his movie as Harris dives into the abyss itself and confronts the NTI's. In its favour, Mastrantonio's embarrassingly one-sided dialogue with Harris as he plummets into the darkness is muted by the amplified strength of their relationship, but the crass manipulation of the audience's emotions remains and the sequence is fatally diluted as a consequence. But that is as nothing to the sudden shift of the NTIs themselves. Admirably as ephemeral as ever (the sense of wonder in the early confrontations is appreciable for this very reason), Cameron is still caught by the abrupt shift from dark claustrophobia to bright and shiny and fails to resolve the problem satisfactorily on either occasion.

The chief restoration here though is the ambitious and infamous tidal-wave sequence, whereby the NTIs endeavour (successfully we assume) to force world peace through the production of two thousand feet high waves off the coasts of all continents. This material - underlined by earlier expositionary footage of newscasts of global tensions on the boil - makes explicit the message of the movie, and as such does benefit this new cut; the sudden shift of events from a tight group to a world stage is neatly affected and does not damage the mood of the piece, or certainly not any more than Cameron's story has already. The director admits himself that in 1989, the NTIs were "toothless", making this essentially momentous contact between man and alien a limp, anti-climactic affair.

Finally then, as Cameron himself has said, any misgivings he might have had about undertaking this return to his past were swept away in the realisation that in many ways, this is a superior work to the film he released in 1989. Much of what was fundamentally wrong then is still fundamentally wrong now - if the NTIs are so all-powerful, why does the Montana crash at the outset; the dreadful misplacing of the film's emotional core so far from the actual climax; the innate cheesiness of the ghastly plastic creation that surfaces at the end minus any sense of necessary awe - but at the same time The Abyss gives us more of what was so good as well, and fortunately without overbalancing the whole. Essentially then, to make this the submerged 2001 Cameron seems to be shooting for is untenable by the very miscalculations he makes from the outset in his plot structure, but at the same time, it would be churlish to deny the sheer spectacle and breathless excitement the first couple of hours provides its audience.