Not every shark movie can be “Jaws.” Or last year’s excellent “The Shallows.” Or even Saturday afternoon cable standard “Deep Blue Sea.” The latest entry in the shark movie subgenre, “47 Meters Down” creates moments of genuine dread and terror-driven giggles (at least for this shark-phobic critic), but its script is dumber than a bucket of chum.

After being broken up with by an unseen – and yet still omnipresent – guy named Stewart, Lisa (Mandy Moore, who had to have signed onto this before the success of “This Is Us“) and her sister Kate (Claire Holt) take a vacation to Mexico. Sitting by the pool isn’t enough for adventurous Kate, and she begs her sister to go on a dive in a shark cage after they meet two Mexican men (Yani Gellman and Santiago Segura). Lisa is (smartly) not down with the experience, especially when she sees the rickety, rusty state of the shark cage on the boat captained by Taylor (Matthew Modine, who apparently didn’t learn his lesson about movies on a boat after “Cutthroat Island“) and receives ominous warnings about sharks’ predatory skills from the world’s biggest jerk, Javier (Chris S. Johnson). “Las gringas no saben nada,” Javier tells one of his crewmates. To paraphrase “The Big Lebowski,” he’s not wrong, but he’s still an asshole.

Mandy Moore 47 Meters Down

Kate wants pictures for the ‘Gram, and she convinces Lisa to get in the cage by shoving her recent breakup in her face because Stewart thought Lisa was boring. Though the sisters’ first moments underwater surrounded by 20-foot Great Whites are exhilarating, their excitement soon turns to fear when the winch on the cage breaks, sending them 47 meters down to the bottom of the ocean. With time – and air – running out, Lisa and Kate try to escape the shark cage while avoiding the predators that surround them and not getting a case of the bends.

Director Johannes Roberts creates a constant feeling of unease, though the film’s rhythm is as off as mine on a dance floor. Some potentially dangerous scenes proceed without event, and they can’t even serve as a respite to the scarier ones. There’s little of the ebb and flow of tension and release in “47 Meters Down,” with the film seemingly lucking into its most fearsome moments. However, it does feature some nice underwater cinematography from Mark Silk, which alternately captures the ocean’s clarity and its murkiness.

Mandy Moore Claire Holt 47 Meters DownThough 90% of the movie is the sisters talking to each other, “47 Meters Down” only barely passes the Bechdel Test. Almost every line of dialogue relates to either Lisa trying to impress Stewart or waiting for Javier or Taylor to save them. If the sharks hunting them are male, it’d get an F. But more worrisome than the test failure is the film’s treatment of the two women in general. Written by Ernest Riera and director Roberts, the script gives meager attention to developing Lisa and Kate’s character traits, other than that they’re both profoundly stupid. Lisa wonders how her butt looks in her wetsuit because that’s what women care about when they’re about to do something exciting. Worse still, her entire motivation for the dive is winning back Stewart, and her shitty sister goads her into it by asking what Stewart would think if she chickens out. And if you think I’ve overused the name “Stewart” in this review, it’s nothing compared to the movie, where it probably occurs in the script more than “shark.”

Not only does the screenplay think that Lisa and Kate are stupid, it treats its audience as though they’re on the same level of intelligence. If you drink every time someone warns about “the bends,” you’ll be in as much mortal danger as the women. “47 Meters Down” overexplains everything, except for its own plot holes.

Mandy Moore Claire Holt 47 Meters Down

*Major Spoiler Alert* Though “47 Meters Down” cheats the audience from its first minutes, it’s biggest con is in its final moments. After showing that Taylor and Kate have barely escaped with their lives, the movie reveals that Lisa is still trapped in the cage, suffering from hallucinations due to nitrogen poisoning. Beyond my hatred of these characters, I could be impressed by the narrative cojones in ending the movie with Lisa running out of air on the ocean floor with her sister dead from a shark attack nearby. But “47 Meters Down” doesn’t commit, and instead finds Lisa being rescued by the Coast Guard. The movie lamely ends with Lisa and her rescuers’ feet from the surface, rather than finishing her story in a satisfying way. *End Spoilers*

Though “47 Meters Down” perfunctorily succeeds in its aims to terrify the audience, it’s not as much fun as it could be due to it’s beyond brainless script, its casual sexism and its idiot characters. I spent most of the movie looking at my watch, eager for sharks to stop coming and for the movie to end. [D+]