Forget "Shiver me timbers!" or any other rousing pirate jargon. The creative equivalent of scurvy has set in on the third leg of this blockbuster voyage based on the theme park ride. The listless Pirates of the Caribbean: At World's End, filmed at the same time as last summer's Dead Man's Chest, rations action and humor, and goes on for nearly three hours to boot.

For the crew -- once again led by producer Jerry Bruckheimer and director Gore Verbinski -- not to have stocked adequate provisions for three epic films is unfortunate but not unimaginable. In other words, you can forgive the filmmakers for repeating themselves a little. But for the movie to be so dark and muddled is inexplicable and eminently avoidable.

There's minimal swashbuckling and lots of talk. Two people are always yammering on about how they regret betraying a confidence or bargain. When the fighting does happen, it's pro forma and murky thanks to camerawork and special effects that are below average for a big-budget yarn. The action-adventure pyrotechnics are disappointing and there's no stirring or coherent story to take up the slack. Confusing double-crosses and half-hearted stabs at comic rigmarole leave the viewer in the doldrums.

After stealing the necessary charts and paraphernalia in Singapore, Elizabeth Swann (Keira Knightley), Will Turner (Orlando Bloom), and Capt. Barbossa (Geoffrey Rush) sail to the end of the world and rescue Capt. Jack Sparrow (Depp) from Davy Jones' Locker. He prefers to remain in that limbo between life and death. The four spend the rest of the movie at cross-purposes trying to outmaneuver one another. At a meeting of the Nine Lords of the Brethren Court -- a rainbow coalition of pirates representing every race and corner of the globe -- they debate how best to regain dominion over the seas.

Chow Yun-Fat joins the cast as pirate Capt. Sao Feng and it's a pretty thankless, nigh on embarrassing task. Rolling Stones guitarist Keith Richards has a cameo as Jack's father. Depp supposedly modeled his swishy, mascara-wearing character on Richards, who looks like he's been subsisting on the ashes of his forbearers and is about to run about of fresh supplies. You can play tic tac toe on his deeply lined face. Whatever you think of Depp, he's a handsome devil who won't look anything like Richards in thirty years, no matter how much rum he imbibes.

Following every shift of allegiance during movie isn't necessary because we're obviously headed toward a clash with the capitalist villain Lord Cutler Beckett (Tom Hollander) who commands the forces of The East India Company, the eighteenth-century equivalent of Enron. The pirate code of honor is held up as more civilized than Beckett's business-only, bottom-line mentality, which permits the hanging of impoverished men, women and children who dare sing pirate ditties.

Complicating matters is a gypsy priestess (Naomie Harris), the love interest of squid-faced Davy Jones (Bill Nighy). Evidently she's the sea goddess Calypso and the Brethren Court decide to free her from captivity. The scene in which she unleashes her fury is one of the movie's biggest letdowns. Elizabeth and Will's romance is barely kept simmering and when called on to provide feeling is about as moving as a perfume commercial. The sultriness and starch Knightley brought to the role initially has been scattered to the four winds. Bloom hasn't advanced very far acting-wise, and Will certainly isn't worthy of taking Davy Jones' place as the mariner of The Flying Dutchman.

At World's End isn't total rot. Jack's hallucinatory encounter with stone crabs and multiple versions of himself inside the realm of the dead is intriguingly novel. Yet there are only minor flashes of the campy, scalawag charm for which Depp snagged an Oscar nomination. Although his tipsy Jolly Roger will be missed, the time has come to put him in dry dock. When Depp is Keith Richards' age and brings Jack out of retirement to relaunch the franchise, we'll be watching.

(Released by Walt Disney Pictures and rated "PG-13" for intense sequences of action/adventure violence and some frightening images.)