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Answer by Ernest W. Adams, game design consultant, author, and professor:
Hardly at all in any respect. The clothing is probably the closest, although it's too diverse and flamboyant, and of course Capt. Jack Sparrow's getup is purely the product of Johnny Depp's deranged imagination.
Sailing a three-masted merchant vessel (no guns) in this period required a considerable crew—I would guess about 30 to 40 at a bare minimum. Remember, only half of them are on watch at any given time. When the Royal Navy took enemy ships, it would put a prize-crew of about 20 aboard, but that was just enough to sail the ship into a friendly port a few days away, and they'd be half-dead when they arrived. But you want to fire the long guns? It takes a crew of about eight to manage each gun of the size we're seeing in the movies, plus a powder-man to run powder and a shot-boy to bring shot from the lockers. So that's 10 more per gun. The crew in Pirates of the Caribbean is nowhere near big enough.
Then there's the problem of getting where you're going. Somebody has to be able to navigate. This means reading the altitude of the sun every day at noon with a sextant and plotting the speed and course traveled regularly on a device called the traverse-board, then transferring it to a chart. To gauge the speed, you throw a log tied to a rope overboard and see how much of the rope runs out in 28 seconds. The compass gives you your bearing. Computing your longitude is far more complicated. This is all tedious mathematical paperwork unsuitable for adventure movies, but we don't see any hint that it might be happening, even in the background.
I was surprised to see one real maneuver in one of the movies: club hauling. This is a way of rapidly changing the direction the ship is facing if the wind will not serve, by dropping an anchor. Normally it's only used in life-or-death situations, because you have to cut the anchor loose and abandon it.
Pirates were thoroughly evil men, but they were necessarily still disciplined sailors; you can't sail one of those ships with a lax, disorganized crew. They were mostly renegades who had fled from other ships. And their officers had to be skilled enough to navigate.
When Robert Louis Stevenson sat down to write Treasure Island, he decided to stick to a schooner—a two-masted, fore-and-aft rigged vessel—because he didn't think he could write credibly about anything larger. This was at a time when people knew a lot more about sailing than they do now, so he knew that he would be open to criticism if he messed anything up. Disney has no such qualms.