From the publisher's website:
Details on pirate strongholds, from the tropical isles of the Shackles to the Varisian city of Riddleport and beyond, present a wide range options for freebooters, corsairs, scallywags, and even government-sponsored privateers throughout the Inner Sea region. Pirate-themed archetypes, new spells and magic and feats, piratical character traits, a pirate slang primer, and more await plunder in this player-friendly book! (Perfect for use with the Skull & Shackles Adventure Path!)
Each bimonthly 32-page Pathfinder Companion contains several player-focused articles exploring the volume’s theme as well as short articles with innovative new rules for social, magic, religious, and combat-focused characters, as well as traits to better anchor the player to the campaign.