Of this, dear moviegoer, rest assured: Dwayne “The Rock” Johnson’s biceps still ripple and glisten in the sun. So do his triceps, pecs, abs, delts, quads, lats and the other 600 or so muscles of the human body.

And that charismatic, multimillion-dollar grin? Still there, too.

But the dude isn’t a magician.

And only a true magician could make something light and fun and fresh out of the unwieldy, derivative and mostly unfunny “Baywatch.”

Now, maybe the filmmakers weren’t thinking light and fun and fresh.

They opted to make an R-rated film, upping the raunch factor of the ’90s TV series starring David Hasselhoff and a slo-mo running Pamela Anderson.

But the R rating doesn’t mean they’ve gone all dark and deep; it just seems to mean lots of raunchy language, sex gags and extended crotch shots.

That last category includes a centerpiece scene involving our two leading men, Johnson and Zac Efron, and a corpse in a morgue.

“Baywatch,” directed by Seth Gordon, begins by establishing the heart and brawn of our main guy, Mitch Buchannon, leader of the Baywatch squad and hometown hero.

We see him hurtling into the water to save a kitesurfer from certain death.

Running along the beach, he ducks into a basketball game to expertly block a shot.

He passes an adoring beachgoer building an elaborate sand sculpture of him.

But his PR-obsessed boss needs to embellish the Baywatch brand, so he brings in a new guy — Matt Brody (Efron), a gold-medal Olympic swimmer who has a bit of an attitude problem (any resemblance to Ryan Lochte is totally intentional).

It seems that after a night of drinking at the Olympics, Brody vomited in the pool and ruined his team’s chance to win the relay.

Brody joins the squad, which includes sexy CJ (Kelly Rohrbach), ambitious Summer (Alexandra Daddario), co-leader Stephanie (Ilfenesh Hadera) and awkward Ronnie (Jon Bass).

Now, if you never saw the TV show, a key point of the plot — though plot is definitely NOT key — is that these lifeguards don’t just save kids in deep waters.

They’re also crime-solvers.

So when a city councilman ends up dead in a boat fire, they figure out pretty fast that he was murdered.

Why? Could this have anything to do with Victoria Leeds (Priyanka Chopra), a club owner whose ambitions for Emerald Bay include some very sinister side activities?

It eventually gets wearisome, despite the best efforts of Efron and especially Johnson.

His mocking of Efron’s character is one of the more amusing themes, including a reference to “High School Musical.”

But darned if that mention doesn’t make you nostalgic for some old-fashioned entertainment or maybe just old episodes of “Baywatch.” In one meta reference, Brody tells the squad that their crime-busting plans sound like “a really entertaining but far-fetched TV show.”

That doesn’t sound so bad, in retrospect.