While exploring the South Pacific’s ancient underground Esa’ala caves, hardened diver Frank McGuire and his dive team, which includes his 17 year old son, his loyal sidekick and the thrill-seeking billionaire who is underwriting the expedition, are trapped underground when a storm floods the cave entrance and blocks their exit route. Forced to swim through uncharted caves to stay ahead of the rising waters, the divers’ courage and endurance are tested as they struggle with each other and the seemingly impossible task of escaping from a watery grave.
Sanctum plays on our primal fears of entrapment and drowning, and 3D is employed effectively to heighten the sense of enclosure and anxiety when characters struggle to squeeze through narrow, water filled spaces. Unfortunately, watching people swimming in underwater caves quickly becomes an exercise in tedium, so in order to head off boredom the filmmakers have loaded the film with extra helpings of conflict on top of the man vs. nature main event: thus we get father vs. son, blowhard billionaire vs. man of action, and everybody vs. his or her own fear and weakness. All this conflict is fine and well, but the tension is largely undone by cliched dialogue delivered through clenched teeth (including a few howlers that elicited laughs from the preview audience). The mainly Australian cast (including Dan Wyllie, soon to be seen in the excellent Animal Kingdom) do what they can when they’re not in the water, which isn’t much apart from a lot of barking, scowling and whinging, but Ioan Gruffudd makes the hammy most of the scene chewing opportunities his villainous turn as the wealthy, arrogant Carl affords him.
As one would expect from a film with James Cameron’s name above the title, Sanctum is very technically proficient, but as I inevitably do while watching anything in 3D, I pondered whether the format was actually adding much to the film visually or narratively. Perhaps if the underwater sequences were set in an ocean, with lots of pretty fish and aquatic flora and fauna, it would have been a real enhancement, but apart from the aforementioned claustrophobic tunnel sequences (about five minutes of screen time), 3D really didn’t improve the film, and in fact pulled me out of the narrative at various points as it usually does. I hope the format will start retreating back into animation where it belongs, although it shows no signs of doing so any time soon.