Sanctum (2011)

A group of cave divers prepare to explore one of the world's biggest caves, perhaps becoming the first humans to discover a new underwater passage to the sea. Among them are the expert caver Frank (Richard Roxburgh), his estranged son Josh (Rhys Wakefield), and Carl (Ioan Gruffudd), the weekend-adventurer millionaire paying for the whole thing. Unfortunately a typhoon hits harder and faster than expected, stranding five explorers inside, and slowly filling the caves with water; now they have no choice but to find their secret passage, or die trying.

Most of the suspense depends on a real, natural human fear of drowning; Buried and 127 Hours played on similar fears to much better effect, but with much stronger characters and performances. Sometimes it's possible, as with Cameron's Avatar, to overlook a movie's lack of human elements and enjoy the hugeness of the event, and the pure rollercoaster ride, but Sanctum feels too little, too late.