Who could have imagined that of all the superheroes in the Superman-led comic stable, the fellow most ridiculed by fandom over the years would anchor one of the most enjoyable movies in the so-called DC Universe? Along with Ezra Miller’s Flash, Jason Momoa’s Aquaman made an auspicious debut in the just-okay “Justice League,” but he gets a full-fledged origin episode in James Wan’s eponymous movie, which happily jettisons the dark, brooding atmosphere that infused Zach Snyder’s vision for the franchise in favor of a lighter, breezier approach akin to the one that made “Thor: Ragnarok,” Taika Waititi’s entry in the Marvel Universe, so much fun.

Like Thor in that movie, Aquaman is portrayed as a slightly dim hunk of beefcake, and Momoa goes with the flow, so to speak. But “Aquaman” is notable not just for its general good spirits, but for creating a shimmering undersea world that’s not only distinctive but strangely attractive, in its own way as engaging as the one in “The Little Mermaid.”

Of course, one must still deal with the fact that “Aquaman” remains, in narrative terms, an obligatory first chapter in what it’s hoped will become a long-running series. Arthur Curry is what would once have been called a half-breed, the offspring of human lighthouse keeper Tom (Temuera Morrison) and Princess Atlanna (Nicole Kidman) of Atlantis, who’s wound up on his dock. Their happiness together is shattered when goons from the undersea realm arrive to drag her back, leaving the forlorn Tom to raise Arthur on his own; we learn later on that she suffered an unhappy fate back home.

The boy grows into a brawny guy who’s his dad’s rough drinking buddy but also a heroic fellow who uses the powers inherited from his mother, and honed secretly under the tutelage of Atlantis’ wise grand vizier Nuidis Vulko (Willem Dafoe), to keep order on the high seas. In that capacity he foils an attempt by David Kane (Yahya Abdul-Mateen II) to commandeer a Russian submarine; in the melee Kane’s father Jesse (Michael Beach) dies, stoking his hatred of Aquaman.

But David has not been acting on his own. He’s in the employ of Arthur’s half-brother King Orm (Patrick Wilson), who aims to use the subs for a fake attack on Atlantis to justify the war he wants to undertake against the land-dwelling world—and unite the various undersea kingdoms under his leadership as Ocean Master. But Princess Mera (Amber Heard), daughter of Nereus (Dolph Lundgren), king of one of the other realms Orm wants to enlist under his banner and unhappily betrothed to him, approaches Arthur, begging him to challenge his half-brother for the crown to avoid a needless conflict.

Doing so, however, will necessitate Arthur’s receiving further training from Mera in the art of Atlantean combat. It will also require the two of them to undertake a quest to find the Trident of Atlan, the first king of Atlantis, which possesses special powers. The combined scepter and weapon is like the sword in the stone: it marks the true ruler and also provides him with the strength to overcome his adversaries, who include not only Orm and his allies, but also Kane, whom Atlantean technology has transformed into the formidable Black Manta.

This is hardly the most innovative plotline imaginable, and some elements of it—like the appearance of a huge sea creature that might well have been called the Kraken but instead is named Karathen—represent a reach too far. But it does allow for plenty of CGI-laced chases and battles, and for a parade of lovely above-wave locations that cinematographer Mort Weisinger, shooting in the IMAX format, takes full advantage of. Still, it’s the abundant underwater sequences, crafted by a small army of effects wizards, that really catch the eye. The images they’ve created add a touch of genuine magic to the proceedings, even if the action sequences set against them can get somewhat muddied amid the swirls.

Moreover, Wan and screenwriters David Leslie Johnson-McGoldrick and Will Beall keep things generally light, accentuating the farfetched tale’s humorous possibilities, especially in terms of the characterization of Aquaman himself, who comes across as something of a likable but sometimes exasperatingly dense hunk. Momoa plays him nicely, balancing Arthur’s beefy confidence and reckless naiveté, and the supporting cast is mostly excellent—Heard strong as well as beautiful, Dafoe appropriately smooth and Abdul-Mateen properly surly. Kidman and Morrison both make the most of the opportunities the script affords them as Arthur’s very different parents, and Lundgren, who along with “Creed II” is enjoying something of a career renaissance, overcomes his makeup to make an impression. Only Wilson seems a bit mismatched as Orm; his natural blandness doesn’t allow the character’s full villainy to flourish.

One shouldn’t ovepraise “Aquaman.” Basically it’s just another in what’s become a seemingly endless stream of superhero movies; but its cheeky sense of humor and striking visuals make it a better-than-average example of the genre.