Great Wight Productions/ Osford Films

Master diver Frank McGuire has explored the South Pacific's Esa-ala Caves for months. But when his exit is cut off in a flash flood, Frank's team—including 17-year-old son Josh and financier Carl Hurley are forced to radically alter plans. With dwindling supplies, the crew must navigate an underwater labyrinth to make it out.

In 1988, Andrew Wight and his team went on to attempt a record cave dive in Pannikin Plains Cave on the Nullarbor Plain, where flash floods turned the expedition into a life-or-death adventure. This was captured on film by his support team, and eventually published as Nullarbor Dreaming. This short film launched his career as an international film-maker and culminated in him becoming James Cameron's right-hand man on many 3D and other film projects. Sanctum was inspired by his Nullarbor experience