“Crawl”

**

(R, 1:27)

Few genres clear out our cinematic sinuses like a rousing creature feature, as was evident even before the animatronic beastie in “Jaws” lunged awkwardly at Robert Shaw’s boat. Working with or without digital assistance, filmmakers like Spielberg and Bong Joon-ho (with his giddy 2007 masterpiece, “The Host”) understood that terror often derives less from a monster’s realism than from its relevance: Is it a credible element of the world it’s terrorizing?

While answering yes to that question might be a necessary condition for giving us chills, it’s unfortunately not sufficient. In the case of Alexandre Aja’s “Crawl,” the presence of a humongous alligator or two in the movie’s waterlogged Florida location is entirely believable. As is the rescue mission embarked on by Haley (Kaya Scodelario), a competitive swimmer, when her estranged father and erstwhile coach, Dave (Barry Pepper), fails to answer his cellphone at the onset of a Category 5 hurricane.

Arriving in the middle of an evacuation, Haley finds Dad trapped in the crawl space of their family home, stunned and minus a chunk from his shoulder. For the next 80-odd minutes, the two will try to navigate a filthy obstacle course of water pipes, electrical cables and rising floodwater, watched anxiously by a raggedy pooch named Sugar. Also eyeing them is a pair of toothily circling predators, who seem set to add Haley and Dave to their noisome floating larder of previously chomped-on snacks.

As “Crawl” works itself into a lather of bloodied limbs and frothing water, Aja — whose slickly savage 2006 update of the Wes Craven cannibal classic, “The Hills Have Eyes,” showcased his mastery of mood as well as grisliness — delivers a smoothly efficient popcorn picture. The gators are gnarly, the manipulation of light and shade is impressive (the plucky cinematographer is Maxime Alexandre) and the claustrophobia is eased somewhat by a barreling pace and the odd check-in with the outside world. Sometimes the critters like to go out for dinner.

Yet while unlucky looters and a friendly cop are swiftly transformed into mangled entrées, our heroes repeatedly, and unconvincingly, resist being gobbled. And though Scodelario is spunky and game in what must have been an extremely uncomfortable shoot, the script (by the brothers Michael and Shawn Rasmussen) is airless and repetitive.

Fans of rampaging-reptile movies will fondly recall Greg McLean’s tautly inventive “Rogue,” which made magnificent use of its Australian Outback locations. Here, there’s not nearly enough to distract us from that mucky basement and Haley and Dave’s emotional healing, signaled by some of the hokiest dialogue this side of a Nicholas Sparks novel. The pair’s matching tourniquets are doing a fine job stanching blood; let’s not ask them to stem resentments as well.