James Cameron has already shown that he likes to dip his creative toe into deep waters with The Abyss, Aliens of the Deep , and to a lesser extent the one he made about the ship that sank. Well his toe is at it again, albeit in a producing capacity this time around, with this damp tale.

Deep, deep down within the South Pacific, exist labyrinthine cave systems, parts of which have yet to be explored by man. Until Now. Frank (Richard Roxburgh) has spent much of his life diving in at the deep end, which is why he and has team are keen to take a further look inside the caves of the Esa’ Ala district. Flying in to join him are his old mucker and financier Carl (Ioan Gruffudd), and Carl’s girlfriend Victoria (Alice Parkinson).Escorting these two new members of the team down to the underground base camp is young Josh, Frank’s son.

The team get understandably excited when they discover a new section of the cave. Despite their obvious keenness to crack on and explore it fully, they attempt to report their findings to base camp above ground. Problem is, comms are down. The reason? The bad weather they were expecting has arrived earlier than expected, bringing with it dangerous flash floods.

Not only do these floods prevent the team from reaching the surface, it means they’re forced to go in one direction only – down. But with limited supplies and even more limited knowledge regarding what’s below them, it’s truly a perilous journey into the unknown.

With an opening reminiscent of Jurassic Park, Sanctum promises to be quite a ride. In part it stays true to this promise, as the audience is submerged into the depths of its impressive underwater world. The fact that it was filmed in 3D actually enhances the viewing experience, just for a change. Light often beams out of the screen, enhancing the sensation of depth all round.

But where it parts waves with the dinosaurs is with its casting and script, both of which have B-movie quality. Gruffudd, who’s probably the biggest name on the bill, more often than not looks embarrassed to be involved in the project; and so he should as he’s far better than this.

It’s not his fault though; it’s clearly down to the choice of director. This is only Alister Grierson’s second stab at directing a feature and he’s clearly out of his proverbial depth here. He’d probably get away with directing one of those underwater jobbies for David Attenborough, but he just can’t cope with a bunch of actors flapping about in wetsuits; their performances make Flipper’s almost Olivier-like.

The star of the show is the actual location; it’s lit well and certainly gives a better account of itself than the entire cast. It does at times feel like watching a 3D version of the classic screensaver though (without the fish), but saves itself with some impressive set pieces. It’s just a shame that the actors had to come along and spoil it with their insipid dialogue.

Cameron’s name may well be used to push this title, but it just doesn’t have any of the scale or ambition of his work.

But if you go into with the lowest of expectations, then you may come out of it pleasantly surprised – just.