‘Just think of the pictures!’ exclaims a smiling girl in a bikini (Mandy Moore) to her recently single sister (Claire Holt), also smiling in a bikini. The sun is shining in Mexico, and Lisa and Kate are feeling adventurous. How can they show the ex what free spirits they are? By watching hungry sharks from the confines of a rusting boat cage, of course. Next thing they know they’re 47 metres below sea level, with oxygen running low and the sharks circling in the murk overhead.
This is the kind of film that exploitation master Roger Corman would’ve knocked out by the truckload in the ’60s and ’70s. Yes, there are shots of writhing female limbs fighting off dead-eyed predators. No, there aren’t any surprises in store. But in its atmospheric soundscape, cinematography, taut characterisation and storytelling, this is a very involving genre thriller.