Forty years after Jaws revolutionised the film industry, sharks continue to break open the box office. The latest example is 47 Metres Down. This aquatic thriller, slated to go straight to VOD, ultimately overperformed dramatically in the U.S.

The film’s first act does little to suggest anything phenomenal – though there is a very cute joke with an overturned red cocktail under the opening credits. A pair of holidaying ladies (Mandy Moore and Claire Holt) meet a pair of handsome lads and end up agreeing to a cut-price shark tank adventure. Moore’s character, Lisa, is adamant from the get-go that their venture is ill-advised.

Oh boy, is it. The winch breaks, and our heroines are trapped underwater (you guess how far down) in a mangled cage surrounded by hungry sharks. What ensues is a cleverly-constructed series of fry pans and fires, framed with relatively realistic constraints (eg they can’t just dash to the surface, at risk of suffering the bends). The middle half of the film is genuinely gripping and surprising, surpassing any budgetary constraints.

The climax is…well, it’s surprising too, but in a way that’ll prove divisive. I didn’t hate it (and it’s certainly heavily foreshadowed) but it’s undeniably silly.