James Cameron is a name that has become synonymous with action blockbusters: Terminator 2: Judgment Day, True Lies, Aliens and Avatar have all been directed by the Hollywood juggernaut. Before Avatar revolutionised 3D technology and broke records at the box office, Cameron was investigating the deep. Deep space has fascinated the director, but deep sea has been just as integral to his career path.

Titanic relayed life on the famous vessel before it plunged to the darkest depths, Aliens of the Deep was a documentary covering unknown species below the surface and The Abyss also explored oceanic phenomena. Cameron's appreciation for the ocean is where the sequel to Avatar will take place, so it's no surprise that the film-maker has been a key component in the making or "testing" of Sanctum, an underwater cave-diving experience in 3D.

The film, set in Australia, has the subject matter of a documentary - following a mixed team of experts and new recruits in the discovery of ancient caverns. Sanctum has tie-ins with The Descent in its claustrophobic cave experience, yet the film doesn't venture into the realm of paranormal. Instead, it opts for a formula we're used to seeing at the cinema in the form of a slasher movie with an equally mediocre script and performances. Instead of a ghost mask, claw or badly burnt face... our antagonist is indistinct, unmmovable and invincible.

Nature is the killer, whether it's the lapping waters, the rocky walls of the caverns or humanity's survival instinct. Our intrepid cave explorers have big egos and are put to the test when a flash flood traps them in one of the world's oldest caves. What started as a risky expedition turns into a nightmare when the team are forced to go even deeper into the unknown in an effort to survive.

James Cameron's name has been bandied about for Sanctum to the point that his brand is its only selling point apart from the supporting role from Ioan Grufford (Amazing Grace, Fantastic Four) as Carl. Richard Roxburgh plays Frank, an Aussie dive master veteran and leader of the group, while Rhys Wakefield delivers as Josh the main protagonist, Frank's rebellious son.

The cinematography and 3D experience is the main draw card. While Cameron's name is emblazoned on Sanctum's movie posters and movie trailers, Cameron is a producer with Alister Grierson attached as director. While the cast look the part, it's predictable story and flimsy characters don't really live up to the full potential of an underwater cave-diving experience or as a follow-up to Avatar.

Sanctum looks beautiful, sounds fantastic and gives plenty of hope for Cameron's sequel to Avatar, but it boils down to a watchable - yet somewhat disappointing man vs. nature thriller. It's the sort of movie where you'd expect some paranormal or alien activity with the right tone for fantasy. Unfortunately, it just doesn't have the gritty reality of a Touching the Void or 127 Hours survival adventure would foster making it a missed opportunity.

The bottom line: Promising.