The astounding visuals almost overcome the waterlogged emotional drama in “Sanctum,” a subterranean survival epic that expertly tightens the screws even as one wishes it would keep a tighter mouth-clamp on its increasingly whiny characters. Sure to remind some viewers of “The Descent,” though it mostly bears the thrill-seeking, 3D-loving fingerprints of exec producer James Cameron, this often squirmingly visceral thriller offers aquaphobes and claustrophobes one more reason, as if they needed it, to steer clear of Australia’s treacherous Esa’ala Caves. Superb imagery, stereoscopic enhancements and Imax showings should give this otherwise midrange-trawling B-movie a commercial shot in the arm.
Though directed ably enough by Alister Grierson (“Kokoda”) and loosely based on true events that befell producer Andrew Wight during an actual cave expedition, this extremely Down Under adventure can’t help but feel pieced together from spare parts of other Cameron-helmed pictures. The abundance of watery mayhem recalls “The Abyss”; the deep dives and 3D visuals bring to mind his documentaries “Ghosts of the Abyss” and “Aliens of the Deep” (both also produced by Wight); and like “Titanic,” “Sanctum” kicks off with a nifty computer graphic that provides a visual and scientific context for the thrills and spills to come. Alas, the similarities to Cameron’s body of work also extend to the writing, with the result that the caves have far more depth than the characters in John Garvin and Wight’s script, while the dialogue is clunky enough to make one wish more of it had been delivered underwater.
Thus, Frank McGuire (Richard Roxburgh, effective), a grizzled hardass who has spent months in the Esa’ala Caves trying to find an elusive underground pipeline to the ocean, is described in passing as “the most respected explorer of our time.” His younger, slicker fellow caver, Carl (Ioan Gruffudd), at one point takes a reckless swan dive off a cliff, spurring someone to point out, “Carl likes to play by his own rules.” And so he does, especially when a flash flood seals off the cave exit and traps the two men underground with Frank’s neglected pretty-boy son, Josh (Rhys Wakefield); Carl’s pretty, and pretty useless, g.f., Victoria (Alice Parkinson); and the unpromisingly named Crazy George (Dan Wyllie).
The key to enjoying “Sanctum” is to look, not listen. Early on, Jules O’Loughlin’s 3D camera prowls the cavern interiors in mostly unbroken takes, allowing viewers to orient themselves within the space alongside the characters (blown up in Imax, the feel is even more immersive). Attention has been paid to every detail of Nicholas McCallum’s production design, particularly the lights coruscating off the pools’ surface and bouncing around the cavern walls. And when Frank and another diver (Allison Cratchley) swim into what looks like a magnificent, sunken cathedral (beautifully lensed by underwater d.p. Simon Christidis), the film allows us to register a moment of genuine awe before terror sets in.
For impressive stretches, the terror is just as genuine. Like “The Descent,” but minus the gollums, “Sanctum” induces an unnerving sense of claustrophobia through formal resourcefulness alone — limited light sources, confined spaces, the painful scrape of bodies against rock in Paul Pirola’s meticulous sound design. Gory moments occasionally cross over into sadism, but that’s par for the course with this sort of clash between man and nature. More problematically, the struggle-for-survival premise is so elemental that the tacked-on character conflicts feel even more banal and screechy as the body count rises: Will Frank and Josh patch up their father-son issues? Is Carl not as trustworthy as he appears? Is Victoria really stupid enough not to wear a wetsuit?
As one would expect from a Cameron-produced film, the 3D is used in an atmospheric rather than obtrusive manner, subtly accentuating the depths and contours of the cave. Pic was shot primarily off the Gold Coast and in caves around South Australia.