Lively lead, but plot has no bite

footage displayed on screens within the big screen.

Collet-Serra does deserve credit, though, for recognising how to build tension – especially during the anticipation of the shark’s initial assault on Nancy – and also treats us to a couple of grisly, B-movie-perfect kills.

The director isn’t helped by a wonky script provided by screenwriter Anthony Jaswinski, who shows all of his inexperience within the field.

Choosing to saddle Nancy with a seagull buddy (yes, this actually happens) is as unnecessary as it is implausible – seriously, not every person stuck on their own in a movie needs to have a Wilson from Castaway-aping non-human chum.

Nancy also has an irritating habit of saying all of her plans out loud, which treats the audience as too dumb to keep up with what’s going on.

The stricken lead is more unlucky than someone who breaks a mirror while standing under a ladder on Friday the 13th as increasingly questionable scenarios play out to drag the film out to its full 80-minute running time.

Lively does a fine job, however, in a hugely physically-demanding role; it’s not quite Leonardo DiCaprio in The Revenant, but the Californian has to cling onto a dead whale, stitch wounds with her earrings and swim through a swarm of jellyfish.

Sadly her efforts are largely in vain as The Shallows fails to build on its intriguing premise.

It’s better than Sharknado, though!