In the late 1700s, Charleston, South Carolina has been overrun by pirates who use the town as a safe haven from which to sell their plunder. One day, Davey Crandall, apprentice to cranky shopkeeper Caleb Nicholas, watches with his coworker, Tom Botts, as the cargo-laden British ship The Liverpool Queen enters the harbor. As soon as the cargo is unloaded and then transferred to the shop's shelves, Charleston territorial governor Gerald Elden brings his charge, Lady Sylvia Copeland, and British aristocrats Lord and Lady Montrose to see the treasures. While Sylvia and Davey flirt innocently, Lord Montrose recognizes a pin stolen from an English friend amid the booty. Although the governor has secretly negotiated with Caleb to sell and profit from the stolen goods, he pretends to be horrified and orders Caleb, Davey and Tom arrested. As the three are marched through the streets, the soldiers guarding them are attacked by pirates, allowing Davey and Tom to escape. Caleb, however, is brought to Elden's home, where Elden shoots him to keep him from talking, and then shocks Sylvia by proposing to her. When she spurns him, he orders her to accompany him to Virginia and, realizing that she loves Davey, vows to kill him. That night, Davey and Tom visit a pirate tavern in the hopes of convincing Capt. Bloodthirsty Ben Wickett to allow them passage on his boat, the Defiance . Although Davey at first impresses Ben with a clever trick, the pirate refuses to board them without payment. To make money, Davey dances on the tavern's stage, but fails to merit attention until he improvises a song about a pirate. Although Ben takes their newly earned money, he plans with his first mate, Isaac Wells, to throw them overboard when they reach the open sea. At sea the next morning, Ben attempts to get the two drunk, but Davey, who is allergic to alcohol, refuses. After Wells sets out the plank for them to walk, however, Davey grabs a bottle for courage, and when his face breaks out in hives, the pirates fear that he has the pox and abandon the ship in a panic. Davey and Tom sail on alone until they spot The Liverpool Queen . Not realizing that their ship sports a pirate flag, they set off their canons as a signal for help. The captain, who is carrying Elden and Sylvia, as well as prisoners headed to debtor's jail, assumes he is under attack and surrenders. Davey sees Elden on deck and realizes he must disguise himself as pirate "Bloodthirsty Dave." After he and Tom board the British ship and round up the prisoners, Sylvia denounces him and informs Elden that she will marry him in Virginia. Dave returns to his ship, despondent, and announces to the prisoners that he will free them if they help him sail to the pirate capital, the island of Tortuga. The grateful prisoners, many of whom are sailors, agree, and within days they reach the island. There, Davey is brought before a pirate tribunal, which includes Henry Morgan, Capt. Kidd, Mistress Ann Bonney, Capt. Long Ben Avery and Blackbeard. They test Davey's supposed killer instinct by pitting him against Blackbeard, and after Davey cuts off the pirate's belt, he wins the fight and is accepted into the brotherhood. He learns that they are funded by a mysterious American, whose messenger Davey quickly recognizes as Elden's valet. Realizing the depth of the governor's corruption, he begs the pirates to help him attack Elden in Charleston, but they refuse and he is forced to go alone. Back in Charleston, Davey disguises himslef as a British aristocrat in order to infiltrate a costume ball Elden is holding for Sylvia. He spirits Sylvia away and, by describing the wedding gown that Elden bought from a pirate, convinces her of her fiancé's unscrupulousness. Elden recognizes Davey, however, and jails him. That night, Sylvia sneaks out to the Defiance and plans with Tom to paint a miniature armada on the lens of a telescope, which will trick Elden into thinking he is being attacked by pirates. She brings Davey the telescope, and when Elden seizes it, he is fooled by the picture long enough for Davey to force him to sign a confession. Davey then races to Lord Montrose's ship, but Elden gets there first and shoots the lord. Just then, Tom and the Defiance crew arrive, and a sword fight breaks out on the ship. Just as Davey chases Elden up a sail, the pirate brotherhood arrives to help. Panicked, Elden drops his sword and plunges into the ocean. In Tortuga months later, Davey, now married to Sylvia, is revered as a powerful pirate. He arranges for a pardon for his fellow pirates, and although they swear to go straight, news of a nearby ship loaded with gold quickly ends their reformation.