Episode #1.1 - S1-E1
Character mistake: In the opening minutes of the first episode, as the Erasmus is struggling through a storm, Blackthorne is told that the boatswain is dead. He checks the corpse and then says, "Get the body aloft," which would entail carrying the deceased up the mast. The correct order would be "Get the body topside."
Factual error: When Blackthorne is on Rodrigues' ship, Rodrigues offers him grog. But grog was only invented in 1740, by British Vice Admiral Edward Vernon, whose nickname was "Old Grog" because of his preference for coats made of grogram cloth.
Vasco Rodrigues: Listen to me, you whore-gutted, pock-marked, motherless scum... I need a favor.