Framed inside euphoric cinematography, “The Shallows” is a brisk film that swells with dread, carnage and pathos. Though, this new shark-attack flick lurches sporadically from feigned sentimentality and peculiar choices in the editing room.

Needless to say, “The Shallows” is like the tide, a series of highs and lows.

The movie sets up like this: Nancy (Blake Lively), a medical-school dropout with an existential need to surf, is reeling from the loss of her mother. She travels from Galveston, Texas, to a “secret” beach in Mexico where her mom once hung ten while Nancy was in utero.

After arriving, Nancy assures her driver and us: “I never surf alone.” But we know this movie hinges on her making such a mistake.

She quickly suits up, grabs her board and heads into the water. Of course.

Before catching her first wave, she converses, in broken Spanish, with two locals out on the water. They warn her of the changing tide, particularly a shallow area that becomes an island during low tide.

This makeshift island will be her sanctuary, prison and doomsday clock.

Whenever a new shark swims onto the silver screen, it’s impossible not to compare the project to Steven Spielberg’s 1975 classic, “Jaws.”

“Jaws” is of the less-is-more approach. Granted, Spielberg got to this school of thought due to incessant complications with his mechanized great white. But no matter. He got there.

Spielberg induced widespread hysteria with what he didn’t show us. People were afraid to dip their toes in their bathtubs thanks to Spielberg’s simple, yet innovative point-of-view shots. And, as a result, it set a precedent that nearly every imitator has since ignored.

Mercifully, Director Jaume Collet-Serra took a page from Spielberg’s book, mostly.

In “The Shallows” we get those patented POV shots. Moreover, the camera often bobs on top of the water – again, a la “Jaws” – and you can’t help but crane for a glimpse of the leviathan below. Collet-Serra rarely offers such relief.

Though, when he does, it’s through some rather convincing CGI. However, as the movie progresses, and the shark becomes more of an onscreen presence, the effects, at times, look crude, venturing into made-for-TV movie territory.

“The Shallows,” if nothing else, is compelling. For a movie set on the open water it invokes an unshakable sense of claustrophobia. This is largely due to one hell of an outing from Blake Lively.

Alone, half naked and splayed out on what’s roughly a six-by-six rock, she trusts Collet-Serra that every groan, scream, wince, flinch and tear isn’t all for naught. And it isn’t. This partnership yields an anxiety-inducing, squirm-in-your-seat experience.

And dazzling cinematography captures it all.

Masterfully alternating angles, perspectives and colors, the camera frames all the horror, tenacity and heartache inside a Babylonian beach.

Even the juxtaposition of Nancy’s onscreen buddy, a seagull named Steven, who is confined to the same rock because of a broken wing, somehow embodies Nancy’s resolve, grief and bout with nature, like a subtle reminder of nature’s beauty and its indifference.

The nadir of the film is when Collet-Serra doesn’t trust his already arresting cinematography, compelled to tack on superfluous visual style. The film’s big surfing sequence, for instance, plays out like an MTV music video. It’s rife with, you guessed it, slow-mo, bass-heavy electropop and a whole lot of showing off, evoking inane bikini flicks like 2002’s “Blue Crush” – not a good look.

Tacked on sentiment that’s written unconvincingly and performed even less so by Brett Cullen as Nancy’s father doesn’t help. The film’s through line, Nancy’s struggle with grief, is sometimes convincing but too often a contrivance.

Collet-Serra’s shark picture offers few layers to peel back, even though it tries. It too often feels like a narrative crafted for a shark rather than around a shark.

Instead, “The Shallows” is everything you might expect from this kind of picture: blood, teeth and lots and lots of thrashing. But with frame-worthy shots abound, “The Shallows” feels a cut above the rest.

On that, and perhaps what it does best, “The Shallows” compels you simultaneously to regard and fear nature, for we are inextricably linked, an element in nature’s composition.

“The Shallows” is rated PG-13 and runs 86 minutes. It’s currently playing in area theaters.