That luckless skinny dipper from the opening of “Jaws” should have grabbed some survival tips from Blake Lively. Just when you thought that “The Shallows” might be nothing more than flashing skin and a few cheap flashes of shark teeth, Lively and director Jaume Collet-Serra (“Non-Stop”) defy expectations. Yes, there’s shameless bikini ogling, but what could have been throwaway exploitation is instead a frequently gripping portrait of dire-straits resourcefulness.
After a dazzlingly efficient opening freak-out — careful what shots you wish for, GoPro users — we meet Lively’s venturesome Nancy Adams down in Mexico, catching a lift to a remote, local-secret beach. She’s chatting with her hang-loose ride (Óscar Jaenada) about the bad choices that have kept a hungover girlfriend from joining her, but Nancy seems to be making plenty herself: hitching alone, surfing alone, not sweating pickup plans. (At least she’s got her SPF 50!)
Still, this setup isn’t handled obliviously, as Nancy brightly vows to be careful, and the script gives her decent, deftly revealed motivation for thinking she can and should make the trip. Personal loss has brought her to the pristine spot, which holds special meaning for her. Plus, she did pick up a thing or two before dropping out of med school, should some unforeseen need arise.
Boy, does one ever. An inventively chilling tube-wave shot gives us our first glimpse of the movie’s shark right before Nancy gets hers. She takes a brutally graphic tumble, and the scene’s underwater tint turns from cobalt to bright red. It’s this arresting color shift and stylish 360-degree shots of Nancy trapped on a rocky protrusion just offshore that distinguish the movie from the isolated peril of “Open Water,” even before we get to the showcase attack effects.
Collet-Sera relies more on cause-and-effect than jump scares to make us flinch, as Lively’s character jerry-rigs a jewelry suture for one gash, then suffers another on a buoy offering her one last reprieve. The movie is blunter about communicating Lively’s desperation at points, giving her dialogue where, say, “All Is Lost” recently demonstrated just how inessential it can be. The action also turns from semi-plausible to absurdly superheroic at the finish, another case where less might have been more. But if there’s one popcorn movie so far this summer that actually makes us fear for — and care for — its protagonist, this is it.
★ ★ ½
Directed by Jaume Collet-Serra. Written by Anthony Jaswinski. Starring Blake Lively, Óscar Jaenada. At Boston Common, Fenway, suburbs. 87 minutes. PG-13 (bloody images, intense sequences of peril, and brief strong language).