Making a movie about a cave diving expedition sounds like a treacherous, expensive, and most likely exhausting feat. Yet, the risk factor is, paradoxically, what attracts filmmakers – the more adventurous they are, the more they’ll get the difficult shots and complex sets and equipment as means to shine.

Perhaps this is just what drew daredevil James Cameron to produce Sanctum. But while difficulties do turn into opportunities when you know how to use them, sometimes hard work is just not enough.

Sanctum tells the story of a cave diving team headed to explore the least accessible, most daunting cave in the world, only to find themselves in serious trouble when nature refuses to behave and a storm ends up effectively trapping them underwater. Panic ensues, along with a stream of previously buried relationship issues, rivalries, and plain old egotistic displays which destroy the divers’ plans of survivals – and also make the viewer wonder why such a broken team has taken on this delicate and dangerous mission in the first place.

It’s human nature – the movie tries to tell us. Yet, the behaviours, feelings and interactions that would make us accept this explanation don’t have the depth and weight required to be truly emotionally effective – simply because the setting and the material effort to visually render this unusual adventure take over everything, effectively undermining the character development in favour of impressive underwater shots and unsettling scenes of danger and destruction.

The actors try hard enough, but their lines are so clichéd that they end up creating a cheesy collage of heard-it-all-before expressions (“He doesn’t play by the rules” is a painful one of them) and soulless attempts to adhere to accepted social values – for instance when the script requires father and son to resolve their conflictual relationship before either survives.

The movie is detailed and well researched – at least to the untrained eyes of the average viewer, who, however, will also coincidentally get confused and distracted by too many technical details and too little chances to actually empathise with the protagonists, no matter how clear their local cinema’s 3D glasses are.

Simple as that, no amount of technology or breathtaking views can instill soul and meaning into a movie that doesn’t have much of either to begin with. Sanctum succeeds in inspiring feelings of claustrophobia, breathlessness, and maybe an urge to run out of the screen and cancel your scuba diving trip, but these are pretty much all the emotions you are going to experience.