Drowning in F/X, Pirates of the Caribbean has all the depth of a theme-park ride.

Navigating by the trade route mapped out for Pirates of the Caribbean: The Curse of the Black Pearl, I reckon we’ve drifted into the Bermuda Triangle of the summer season, where movies disappear in front of our very eyes. Dead men tell no tales, the sea chantey goes, but neither will ticket buyers after sitting through this F/X-rattling Disney feature based on the Disney theme-park attraction and founded on the Disney notion that American character is best strengthened by exposing children to the horrors of computerized skeletal buccaneers: Minutes after we’ve left behind the clatter and spectacle, all remembrance of plot vanishes.

What remains is an unreliable memory of Johnny Depp, whipping up the weirdest gale force of character wind since his thespian role model, Marlon Brando, populated ''The Island of Dr. Moreau.'' And under the circumstances the actor’s eccentric capering counts as welcome entertainment. Though it’s never made clear why Depp’s Captain Jack Sparrow is such a campy chappy -- the only begotten son, perhaps, of rum-pitchman Captain Morgan and the Madwoman of Chaillot -- at least Depp’s nutty feyness is something fresh in a summer of freeze-dried adventure pics.

In all other regards, ''Pirates'' steams ahead on a mirthless course of script beats and busy action sequences, coldly steered by director Gore Verbinski (''The Ring'') to the boom-blast-blare coordinates of producing commodore Jerry Bruckheimer. (A boom-blast-blare score by ''Gladiator'' cocomposer Klaus Badelt proves that if suspense takes place without drums and horns to announce it, it don’t mean a thing.)

In the hurly-burly saga devised by Ted Elliott, Terry Rossio, Stuart Beattie, and Jay Wolpert, and written by Elliott and Rossio (who struck real gold cowriting ''Shrek''), Sparrow is a freelance gentleman-rogue operator out to recapture his ship, the Black Pearl, which has been stolen from under his fluttering fingers by his nemesis, the floridly villainous Captain Barbossa (an expansive Geoffrey Rush, who knows exactly what kind of grog he’s sloshing in). Sparrow’s ally is blacksmith-with-a-past Will Turner (''The Lord of the Rings''’ Orlando Bloom), who partners up with the pirate for his own romantic reasons: Held hostage aboard Barbossa’s cruise to nowhere, Turner’s beloved, Elizabeth Swann (''Bend It Like Beckham''’s Keira Knightley), daughter of a British colonial governor (Jonathan Pryce), fights for her freedom.

It’s ornate and breathless, this hoopla of a pirate story about honor and thievery and drawn swords and gilt buttons; the movie is also undecided about whether to emulate the dashing tradition of ''Treasure Island'' and ''Captain Blood'' or, in bloodless postmodern style, to wink at what it appears to honor. Knightley, all peaches, cream, and pout, huffs prettily as an adventuress trapped in the life of a corseted young lady. Bloom, a true heartthrob, makes a fitting swain. Human interaction, though, is only a time waster between theme-park displays of CGI prowess, in which Verbinski -- never a visual minimalist -- seizes on the ghoulish creepiness of Barbossa’s pirate crew, haunted as they are by a curse that keeps them dead-but-not-dead men. (BBC America fans will enjoy seeing skinny Mackenzie Crook out of ''The Office,'' playing undead.)

It’s back to Depp we go, then, fascinated, if nothing else, by the way he commandeers the movie with his every barmy line reading. ''The Pirates'' production notes cheerfully report that the actor ''developed his ideas for the character of Jack while reading the script in his sauna,'' and that he ''had strong ideas about Jack’s attitude and appearance.'' Waving his pinkies in the air, rolling his eyes rimmed in glitter-rock shadow, lolling languidly, and speaking in a mysterious, slurred accent inspired in part, he has said, by Rolling Stones guitarist Keith Richards and Looney Toons’ Gallic skunk Pepé Le Pew, Depp certainly has character ideas. But who is this exceedingly unbuckled swasher?

And is the laugh not only on the conventions of the genre, but also on us? ''Pirates of the Caribbean'' is so bifurcated a project -- half perfunctory action saga, half Monty Python festival of theatrical mugging -- that a ticket to the thrill-less ride may result in the altogether more alienating sensation that no one’s in charge -- indeed, that for two and a quarter hours, a twisted battle for control has been taking place between Verbinski/Bruckheimer, who demand a vertiginous historical thriller, and Depp, who fancies a bit of arch vogueing while sporting shells in his braided hair.

There may be nothing more fun for actors than experimental exaggeration, especially when filming on a Caribbean island. But there’s nothing that makes an audience feel less welcome than not being in on the joke.

Grade: C