Some 30 years ago, a Maine lighthouse keeper named Tom Curry (Temuera Morrison, “Occupation”) discovers a woman washed up on the beach during a storm. It turns out that her name is Atlanna (Nicole Kidman, “Boy Erased”); she’s a princess from Atlantis on the run from an arranged marriage. Initial distrust quickly turns to affection and then love; Tom and Atlanna fall hard for one another and wind up having a baby boy they name Arthur.

But when Atlantean forces come to retrieve her, Atlanna realizes she has to leave to protect both Tom and Arthur. She returns to Atlantis, leaving Tom to raise Arthur alone.

Present day, young Arthur Curry has grown up to become the superhero known as Aquaman (Jason Momoa, TV’s “Frontier”). He’s doing some ocean-related heroics – for instance, he thwarts a group of pirates led by a fellow known as Manta (Yahya Abdul-Manteen II, “First Match”) and winds up with a sworn enemy – but mostly, he just wants to crush beers and bro out and just be a dude.

Meanwhile in Atlantis, Arthur’s half-brother Orm (Patrick Wilson, “The Nun”) is king; he’s primed for battle against the surface world despite the advice of his vizier Vulko (Willem Dafoe, “At Eternity’s Gate”). His plan is to unite the undersea realms under his rule and become the Ocean Master; his first ally is King Nereus (Dolph Lundgren, “Creed II”), ruler of Xebel.

Nereus’s daughter Mera (Amber Heard, “London Fields”) seeks out Arthur in hopes of convincing him to come to Atlantis and take his rightful place atop the throne as Atlanna’s first-born. While Arthur isn’t interested, Orm’s actions soon force his hand; he has no choice but to fight. That fight takes him all over the world in search of a fabled trident that has the power to defeat Orm’s armies – assuming that it actually exists.

For my generation, Aquaman was the comics character who served as shorthand for “lame superhero” and inspired hundreds of hacky jokes – all along the “he talks to fish!” theme. It was such a trope that it wound up as a major joke in the “Entourage” TV series.

And yet … “Aquaman” is really pretty good.

The reason that it works is that it is not even the least bit apologetic about how cornball it is. It is big, grunting action powered by rippling muscles and gobs of attitude. From our first introduction to Aquaman – an extended fight scene aboard a submarine – it’s clear what we’re dealing with; every witticism, every flex, every raised eyebrow is punctuated by a squealing guitar lick. “Aquaman” is goofy and messy and sprawling, hyperactive and jokey … but it isn’t bleak. It isn’t varying shades of grimdark gray. It is unabashedly itself, and by not taking itself so seriously, it allows room for some actual fun.

And “Aquaman” is legitimately fun. Director James Wan is a great fit for a movie like this; he has genre bona fides – he directed the first two “Conjuring” movies, the first two “Insidious” movies, the original “Saw” and “Furious 7.” This is a dude who wants his audience to enjoy themselves. He treats the material respectfully but not too seriously, resulting in a just-right tone.

Visually, the filmmakers embraced the aesthetic flexibility granted by the undersea setting. The various kingdoms are rendered with beautiful vividity, while the denizens of the deep are presented in assorted flavors of colorful weirdness. The movie has a phenomenal look, and if some of the logistic aspects don’t make perfect sense, well … no biggie. You’ll be able to suspend your disbelief.

Momoa is the perfect Aquaman if you’re making this “Aquaman.” He’s all long hair and abs and edgy charm – basically an anthropomorphized wallet chain. He definitely has the charisma for a part like this, though he probably doesn’t have quite the range for much more – it feels like this is mostly just his persona. The supporting cast is legit. I mean, Nicole Kidman AND Willem Dafoe? Come on. Both are having fun. Amber Heard is hit or miss for me, but she definitely works here; she and Momoa are surprisingly effective together. Wilson is clearly delighting in his bad guy-ness; Abdul-Manteen is really good too.

So yeah – “Aquaman.” It’s easily one of the best entries in the DCEU, a significant shift in philosophy and tone that we can only hope extends to future installments. Yes, there are issues – the plot meanders in the middle and it’s 20 minutes too long – but those are minor quibbles. It really is pretty good.

Come on in – the water’s fine.

[4 out of 5]