You have to wonder why anyone would bother making a shark movie. Jaws was a benchmark and Sharknado 4 was a white flag. There have been many in between but can you remember any? I’ve seen loads and only two –  Deep Water and Deep Blue Sea – are vaguely memory stirring, and even the Jaws sequels were lame. But this one is different.

A young blonde girl, Nancy Adams, (Blake Lively) finds the secret Mexican beach her dearly departed Mum had told her about. She’s running from death and Med school to catch a few waves. She makes a series of mistakes that usually make her a deserved candidate as shark-kill: She goes out for a final surf at dusk, on her own, is curious about a floating dead right whale and she’s a hot looking blonde. Normally, it’s pass the Chianti, this girl is done.

But this one has enough smarts to survive an attack, climb a dead whale, then get to a small crop of rocks just above the waterline. She painfully patches herself up before a countdown to high tide starts the tension-o-metre.

It’s also ramped up by some great underwater photography and here’s a surprise: a strong acting performance by Lively. This becomes a mini ‘127 Hours’ test of character. She’s no James Franco because she’s Blake Lively, and she’s good. Her genre-breaking performance stops this becoming a farcical shark porn flesh fest, even though director Jaume Collett Serra tries and tries. The bikini-body shot close-ups are a little too distracting.

But you do care about Nancy and Steven the seagull; and you do feel your gut tighten, as this is a mother of all-Noah sized sharks.

The other surprise is that the secret Mexican beach is actually on our Lord Howe island, and the Queensland film board invested. The beach looks brilliant, but the four-foot waves aren’t that amazing and as the titles says – it’s shallow. Hardly deep enough for a mega-shark to feed in and launch attacks from.

But, let’s face it, this is a shark movie and if you want to start questioning why the great white shark is so determined to kill, perhaps you should wait for Shark week on Discovery channel. This genre requires suspending belief and the story has more holes than Nancy’s wetsuit, and a crazy unpredictable finish is part of the deal. And this one had the audience in stitches. (I’m pretty sure it’s what the writer and director expected. It’s too ludicrous for them to anticipate anything else.)

It’s no Jaws, but it’s a very tight and lean thriller; certainly one of the best of its genre and will launch Miss Lively as an actor, which can only be a good thing.

So, if you want to munch on a box of popcorn, be frightened and walk out with a smile, take a swim into these shallows… just don’t dive in too deep.

Con’s Score: 3.5 dorsal fins

Con Nats – Talking Arts