Well, we have our new Errol Flynn: a little pudgier, not as handsome, but just as compelling as anyone who ever strode the quarterdeck. Director (and cowriter) Peter Weir has recognized that Russell Crowe can take over any screen he has a mind to, and gives him free rein in "Master and Commander: The Far Side of the World." Crowe's expressive face and deep voice give him a presence that no one else I can think of compares with. And when he plays a wise, brave, thoughtful, brilliant tactician - as he does here - as Captain Jack Aubrey of his majesty's ship Surprise, we are captivated almost every moment of the film.

The film, set in 1805, is taken from parts of two books in Patrick O'Brian's series of twenty novels about Aubrey and his friend the ship's surgeon Stephen Maturin (Paul Bettany), all of them set during the Napoleonic wars. Where in the novels Maturin is a counterweight to Aubrey (he is also a spy, with his own agenda that is not known to Aubrey), here he plays a definitely subordinate role; he is the intellectual to Aubrey's practical man. In this stripped-down slice of naval warfare, though, we do not miss that other plot.

The Surprise has been given the job of tracking a French warship, the Acheron, that's headed to the Pacific, and then must capture it if possible, destroy it if not. But the Acheron is bigger, better armed, and better built than the Surprise, and so it will be Aubrey's job to find a way to overcome those handicaps. As the film opens the Surprise comes unexpectedly upon the Acheron off the coast of Brazil, and must fight a battle though barely prepared. Weir sets the stage and shows us the battle as though he were shooting a documentary. It is a brilliant set-piece. And more: while watching it we get insights into the sailors on board, the structure of the naval hierarchy, and the personality of Aubrey. Both ships survive, of course, and the Surprise limps away to repair itself.

Then the film spends time as an observer on the ship, as the Surprise moves closer to a final confrontation with its nemesis. Sailing through storms and calm, including a stop at the Galapagos Islands, we get to know the crew, and the relationship between Aubrey and Maturin, who play violin and cello duets in Aubrey's cabin. We see the nature of discipline and the ways in which Aubrey is the master of the ship, and it is not always pleasant. Crowe plays him as a man to whom command is second nature, but who respects and cares for his men, who likes to drink and tell jokes (which his subordinates have no doubt heard many times before), and is most alive as a tactician.

The film is as exciting to watch as any naval epic I can recall, with vignettes that give depth to many of the sailors. A very young midshipman (Max Pirkis) whose voice has not yet changed, is given unexpected responsibilities. Another, now almost thirty, must face that he is incapable of command. And so on. The tensions, the unexpected warmth, the terrors and the pleasures are all here for us.