Some background in case people reading this don't know: Master and Commander: The Far Side of the World is a movie that mixes in plot elements from at least a couple of Patrick O'Brian's naval series, with some details change to reflect the time when it was filmed (ex: the fictional Surprise chases after a French ship in the movie, whereas the fictional Surprise in the books was after an American.)

O'Brian had a deep fascination with the Royal Navy of Napoleon's time, and did a great deal of research not only with primary source documents but secondary literature in the writing of his books. Aubrey's naval exploits often closely follow those of Lord William Cochrane, the 1st Earl of Dundonald, a colorful figure whose taking of the Spanish frigate El Gamo with his brig HMS Speedy forms the centerpiece of the first book in the 20-book series.

Anyhow, the series of books themselves offer some fairly complex characters for the director, Peter Weir, to work with. Substantial scenes for the movie were filmed on a replica British frigate, originally built in 1970 as a replica of HMS Rose, and the material culture of the movie itself is spot on -- the crowding portrayed in brief shot belowdecks and also on the deck of the ship is the result of filming on the ship itself. There are a few things that I would take issue with from a pure "historical" standpoint -- some scenes belowdecks exaggerate the height of the decks, for example in the dinner-table scenes, but attempting to film with an overhead height of 5' would have been difficult to shoot otherwise. But the everyday dress of the sailors, the depiction of the food they ate, the scenes of singing on deck, etc., are all as accurate as anything I've seen.