Jules Verne’s 1874 novel—a sequel to “Twenty Thousand Leagues Under the Sea”—has been adapted for the screen numerous time, most notably in a 1961 British film that served as a vehicle for some of Ray Harryhausen’s best stop-motion effects as well as a spectacularly vivid music score by Bernard Herrmann. This new take on the story is hardly a faithful reflection of the book, instead serving as a sequel to 2008’s kiddie-aimed updating of Verne’s “Journey to the Center of the Earth” and, like that movie, little more than an orgy of CGI gimmickry and obvious 3D business. “Journey 2,” as it’s called (with Verne’s moniker relegated to a subtitle), is perhaps adequate as a surrogate babysitter for parents of pre-teen boys who need a ninety-minute rest from the kids’ constant badgering, but is otherwise even less engaging than its predecessor.

The conceit, once again, is that Verne’s books weren’t fiction, but reflections of actual places, and young Sean (Josh Hutcherson, reprising his role) is drawn into them. This time around, the troubled boy is accompanied by his stepdad Hank (Dwayne Johnson) on a search for Verne’s mysterious island, where the boy—a student of Verne’s secret messages—believes he will locate his grandfather Alexander (Michael Caine), who was similarly obsessed with the writer’s work. With an okay from Sean’s oddly permissive mother (Kristin Davis), who hopes the adventure will help them bond, Sean and Hank go off to the South Pacific to find the place, hiring a goofy helicopter pilot named Gabato (Luis Guzman) for transport. Gabato’s pretty daughter Kaliani (Vanessa Hudgens) tags along, which allows a puppy-love subplot to emerge.

What follows is entirely predictable. After surviving a terrible electrical storm the group finds the island—Atlantis, as it turns out—where giant beasties have survived from prehistoric times, as well as the crusty but genial Alexander. They’re pursued by a variety of humungous critters, with the chases punctuated by periodic bouts of lame dialogue and particularly deadening bits of comic business from Guzman, while a volcano belching in the distance threatens to engulf them in lava. It’s all a race to find the Nautilus, the late Captain Nemo’s old submarine and their only hope of escape, with the ending never in doubt (though it takes a lot of absurdity to get there).

The actors don’t seem terribly engaged by the material, knowing full well that they’re always going to be upstaged by the effects, supervised by Boyd Shermis, which are decent if not great, and to which director Brad Peyton defers all too readily. Johnson, a former pro wrestler, gets to show off his pecs while going over-the-top to sell the cornball (even croaking out an embarrassing rendition of “What a Wonderful World” at one point), while cameraman David Tattersall focuses a bit too often on Hudgens’ lithe form, (shown off in shorts and tank-top), sometimes in the slow-motion he’s far too enamoured of, though the actress herself proves an energetic presence in Disney Channel mode. By contrast Hutcherson seems to be playing things by rote, perhaps nonplussed at having gotten stuck in a franchise at least a few leagues lower than “Harry Potter,” and Caine offers little beyond his patented vocal delivery, looking as though he couldn’t wait to shave—he really resembles Gabby Hayes here—and pick up his check. Andrew Lockington’s brassily rah-rah score has none of the imagination of Herrmann’s.

So-called family films are a big part of studio output nowadays, and the “Journey” series—which, if the ending is any indication, appears destined to continue beyond this installment—at least isn’t a crummy computer-animated example. But if your children can be induced to sit still for a far slower-moving picture from a bygone age, the 1961 “Mysterious Island” is actually a lot more fun than this one, though of course it’s not in the inevitable 3D.