The Mississippi River: home to grand old paddle steamers, blues music, Huckleberry Finn, and... pirate ships.

With its skull-and-cross-bones flag flapping in the wind, and swashbuckling captain at the helm, this is perhaps the last boat you'd expect to find on America's most famous inland waterway.

But the 12-meter Gypsy Rose II is just one of six pirate ships built by 54-year-old Captain Tim Woodson and setting sail on the iconic river.

Now the buccaneering boat has been sold to the History Channel for $80,000, after being advertised on classifieds website Craigslist.

"It's probably the most photographed ship on the Mississippi River," Woodson, from St Louis in Missouri, told CNN.

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"We get a lot of kids running along the shore, trying to catch the cannonballs as we go by," he said, referring to the 4-inch sponge balls shot from the ship.

Dream boat

The professional boat builder first started making pirate ships five years ago, converting ordinary house boats into fairytale vessels.

"I wanted to find an old boat that I could transform into something really cool," said Woodson.

"My girlfriend asked: 'What are you going to do?' I don't know where it came from, but I said: 'I'm going to build a pirate ship.'"

That's exactly what he did, adding fake masts and covering the boat in planks of wood stained with varnish and black spray paint.

"As you walk on board you see a skeleton wearing an eye patch -- that's the old captain we pillaged the boat from," said Woodson.

"The sails are all torn with cannonball holes," he added. "Inside, the first thing you see is a hand-drawn map, globe of the world, and an old desk covered in treasure."

Luxury living

The remarkable boat may appear to be something out of a 17th century European fable, but inside it has all the luxuries of a modern ship.

Woodson spent just over two months building Gypsy Rose II, which can hold around 30 passengers.

It features two bedrooms, a bathroom, kitchen, and putters along at 30 kilometers per hour.

"The galley is fully functional but is stacked with rum barrels and pewter mugs," said Woodson.

"It really is a modern-day pirate ship with 1600s treasures scattered throughout."

Costume drama

With his battered hat, ripped vest, and dangling earring, Captain Woodson is every inch the pirate of old.

Alongside his girlfriend, Wench Maria, he can be found steering his fantastical vessels from Missouri to Illinois as part of sightseeing tours down the murky Mississippi.

Groups can also rent the boats for pirate-themed parties, with one elderly woman recently celebrating her 99th birthday on board.

"When I was a kid, pirates were cool and that hasn't changed," Woodson said. "It's about that feeling of being free, of being an explorer."

"It gives you an excuse to be the bad boy."

One man's fleet

Among Woodson's six converted pirate ships are a former 21-meter U.S. troop carrier and another 12-meter boat now lined with 18 bunk beds for school trips.

Once complete, each boat is advertised for sale on Craigslist, with the History Channel snapping up Gypsy Rose II for its TV series Ax Men, which follows the history of timber cutters.

Other boats have been bought by cruise operators and restaurateurs.

"When I was building my first ship, people would say I was crazy," said Woodson.