The gulf is wide. For every viewer who found "Pirates" too fluffy, two will complain that "M&C" is joyless. And that will indeed hold true for those with little curiosity about the vanished era this film details. On the other hand, the legions who made Patrick O'Brian's series of historical novels best-sellers will be thrilled. Weir and his production staff have given themselves fully to the world of tall masts and billowing sails, and the movie is a tactile triumph. The claustrophobia below decks, the snap and flutter of giant sails, the crunch of cannonballs through thick wooden planks — Weir and company put the viewer there. They also fill crannies with little bits of business that flesh out the illusion of being on a warship, stuff so minor (like belowdecks panels being moved around to ready for battle) that their absence wouldn't have been missed. Naval-gazing sticklers for nautical authenticity will have a field day.

Hoping to convince others to buy a ticket as well, marketing folks and friends of the film are playing up the presence of manly-man Russell Crowe, whose name is rarely far from the word "Oscar" in advance buzz. If there were ever a chance for this gifted actor to step aside from the awards race with dignity, this is it; Crowe's Capt. Jack Aubrey may saw on a violin to relax between battles, but in this movie he's second fiddle to a big ol' boat, and there's no shame in that.

That ship, the HMS Surprise, has been sent on a mission of grave import when this tale begins. Aubrey and his men are to find the Acheron, a French vessel in league with Napoleon, and either sink or capture her. But the Acheron is mighty, swift and mysterious — it boasts twice the guns and twice the men of the Surprise, and on two occasions it makes the English ship eat its name for breakfast. Not only is the Surprise not guaranteed to take her prey, she'll be lucky to make it back home in one piece.

Capt. Aubrey, as one might expect, has tricks up his sleeve. Weir and co-screenwriter John Collee do an exciting job of making complicated maneuvers comprehensible to the civilians in the theater, and the movie even gets a restrained but very welcome bit of comedy out of one complex fake-out. Aubrey's best friend, ship surgeon Dr. Stephen Maturin, may be a little too transparent as a stand-in for the audience; but he serves the purpose, giving Crowe and the screenplay an opportunity to spell out what the sailors in the film already understand about mid-sea warfare. There's a little bit of friction between the friends mid-way through the tale, with Dr. Maturin playing humanist Bones to Aubrey's ever-bold Captain Kirk, which skirts the edge of cliché. But little is made of it, and the plot's flow hardly suffers.

As impressive a sensory and intellectual experience as "Master and Commander" is, it never entirely settles on a tone that's satisfying for those not pre-sold on the genre. It is neither jaunty nor deathly grave, but it tilts with the waves in both directions. The end, in particular, is a bait-and-switch that only makes sense when "Far Side of the World" is viewed as one chapter in a serial; but serials are best with more fun and fewer frowns. There was never any chance that Johnny Depp would swing swishily into the frame, in "Pirates," but a tiny bit more joy in those cries of "ahoy" in "Master and Commander" wouldn't have killed anyone.