When The Shallows opens, it feels different.  A helmet, complete with attached GoPro camera, bobs on the shallow shore line.  A boy totters along the sea weed strewn beach.  There looks like a piece of half buried surf board a little way up.  Stolen details for certain, but the kind of glimpses at the introduction of a movie that makes you feel like you're in on it.  A silent understanding between you and whomever is going to be spinning this sea-salted yarn for the next 90 minutes, that not only will you notice the clues carefully laid out, but that you'll be rewarded.

The first act is an understandable step back.  Blake Lively's Nancy Adams has come to the same beach her mom came to surf, when she found out she was pregant with Nancy - erm, ok.  Then she speaks to her sister - fine.  Then the phone gets passed over to her dad, who tells us that not only is Nancy dropping out of Med School, but it's a result of her mother's death - just stop.  It's an uneccessary contrivance so painful you'll feel like you cast out to sea and turned around to see a teen movie rather than a survival thriller.  You'll try to shake it off, but the the movie's already started to take on water.  To add to your discomfort, there's some unsettlingly needless shots of Nancy as she gets ready to go into the surf.  Even the most prudish cinema-goer understands that pretty bodies sell tickets, so as long as 15 year old boys are financing what could be a spiritual sequel to Jaws, what the hell!  The problem is that even the camera feels like it's crossing a line.  Unable to decide whether to soak up Lively's beauty like a landscape or out-and-out titillate, instead it meekly steals glances as if it shouldn't even be looking.  The result is slightly disquieting and an odd lack of commitment for a film that could quite easily please the Exec Producers and move on, much like the superfluous backstory.

Thankfully, it doesn't waste much time before diving into it's premise and the cat and mouse game begins. There's some wonderful touches, like the threatening shadow in the wave before Nancy is thrown into the water and the menacing dorsal fin we've come to love in these sea-fairing tales.  There's also a genuine menace even when the shark is no where to be seen.  The desperation too, is skillfully tightened like a knot.  But it doesn't last long.

The problem is it's a little too interspersed.  Once the breaths of your goodwill have been drowned out, it's hard to come back up for air.  Even efforts to sustain tension with the mildest request for suspension of disbelief just feel silly.  A jelly fish gauntlet is eye-roll inducing, when it should be worryingly tense and if you don't completely check out when Nancy somehow remembers that her fishy nemesis didnt like coral, why not finish up with a Sharkando double-bill?  Even a cheeky Jaws homage becomes mutliated, not in it's execution, rather in it's indecision to be popcorn-fare or genuine adult thriller.

Much like her husband's surprise hit Buried, Lively does everything she can to carry a film that focuses on her in one place for it's duration. The film just seems to ignorantly make the wrong calls before she can bring it in to harbour.

2* - Deep Poop Sea