The dumb movie “Whalefall,” about a man who gets swallowed alive by a whale, lost me countless times over its increasingly ridiculous oceanic voyage. 

But never more so than when the human meal, Jay (Austin Abrams), grabs a jellyfish and uses it as a flashlight while inside of Moby-Dick. Even MacGyver would roll his eyes at that one. 

It’s best not to overthink a reboot of “Jonah and the Whale.” Yet turning one’s brain off to the extent that this preposterous movie — a combo of “The Poseidon Adventure,” “The Meg” and weirdly “The Lion King” — requires is next to impossible. 

If the ticking-time-bomb goal is for Jay to survive and, well, avoid emerging out the other end in an altogether unpleasant new form, we have to believe that he’s in real peril.

But the setup and execution are much too brow-raising for that.

How, during an accidental fish endoscopy, is Free Willy’s digestive tract — throat, stomach, etc. — so conspicuously well lit? Everywhere is illuminated even before Jay finds his absurd trusty bio-flashlight more than an hour into the film. With groovy blues, greens and oranges, this thing’s esophagus looks like a 1970s basement.

What are the strange anemone-esque appendages that attack Jay like he’s on a theme park ride? They appear less functional to food motility and more like genuinely pissed off cobras.

How on Earth did he remember to bring an unopened package of steel wool on a spontaneous, emotion-driven scuba dive?

There are a million such questions. And they’re all buzzkills, of course. Perhaps the answer every one is: Shut up and just enjoy it. However, “Whalefall” is not a terribly exciting or engaging movie either, despite the enthusiasm of its star on the rise, Abrams. 

This is the second flick in a month (much better “Resident Evil” is the other) in which funny Abrams races against the clock to find safety while mostly just hilariously muttering and cursing under his breath. That can be very amusing to a point.

Yet director Brian Duffield can’t sustain suspense and interest all the way through his thriller episode of “The Magic School Bus.” Ten minutes of Jay being inside the whale is more than enough.

And so Duffield and co-writer Daniel Kraus, who based it on Kraus’ popular novel, tries to force some blubbering to pad it out. 

At the start, Jay’s diving-expert dad Mitt (Josh Brolin) kills himself by jumping off his boat. 

Mitt was a jackass who acted like a boot-camp officer with his poor kid. Still, wanting closure, Jay goes swimming on that fateful day to try to recover a piece of pop’s lost body. “Just one bone,” he says. In the ocean, even that’s a stretch. Two minutes later, Jay’s fish food.

Brolin is extremely annoying in flashbacks to Mitt brutishly attempting to teach Jay about his trade. I can’t remember a more unappetizing performance from him. As bonkers as “Escape From The Giant Water Mammal” is, I’d take that over the strident daddy-issues B-plot any day. 

That stuff is somehow more overblown than a guy being stuck inside a whale. During one flashback, a fed up Jay gets off the boat and swims to shore.

“You’ve got soft lungs!,” dad yells. And then he doubles down for the people in the back. “Soft lungs!”. A laugh escaped my body right then, and “Whalefall” could maybe find an audience among those who’d love to mock it.

Elizabeth Shue plays Jay’s mom Zara, but Shue’s got nothing to do.

The gist is that much of dad’s cruelly imparted wisdom actually stuck with Jay, and as the oxygen levels drop he hears Mitt speaking calmly in his head like Mufasa. He pieces that advice together to find a way out of the creature. 

Jay almost gets there about an hour in when the sperm whale briefly surfaces. He is able to climb halfway up its mouth when he hears a tour boat outside.

“Help me! I’m inside the whale!,” Jay yells.

Look, it’s not quite “I’ve had it with these motherf–king snakes on this motherf–king plane!,” but that vibe is this movie’s best hope for survival.