Edward Kenway is no pushover, he's a bonafide badass. So when he strolls into a bar or tavern, he's not just looking for a drink to satiate his thirst, he's looking for trouble.
Whether it's the obvious stare at some other man's girl or perhaps spilling someone's drink, Edward's sure to piss someone off one way or another.
The real reason you'll want to unlock these Taverns is because once you dispose of all the goons, the barkeep will sell you information regarding secret treasures for 200 Reales.
Don't worry though, beating up thugs is super easy. Just watch out for the counter signal and knock them all out one by one.
Here are the locations for all the Taverns as well as the secret information they contain. Remember to look out for icons on your map with large white bottles.
Andreas Island (573, 720) - Location of the treasure Map in Castillo de Jagua
Salt Key Bank (496, 629) - Information about a Naval Convoy
Crooked Island (808, 545) - Location of the treasure map in Punta Guarico
Arroyos (192, 565) - Location of the treasure map in Santanillas
Corozal (37, 266) - Location of the treasure map in Cayman Sound
Grand Cayman (392, 325) - Location of the treasure map in Isla Providencia
Kingston (623, 172) - Location of the treasure map in Misteriosa
Ile à Vache (839, 137) - Location of the treasure map in Punta Guarico