From the back cover:
"Sail the REAL Seven Seas!
Take your d20 System campaign to a new century of adventuring and discovery. This is the essential guidebook to role-play 18th Century pirates and privateers in the Caribbean. This book is loaded with historical information on life at sea, the political division of the New World, and colorful characters such as Mary Read and Anne Bonny that made pirates into legends. Includes five new character classes, three character class templates,and four new prestige classes. There's also a host of new feats and skills, rules for ship-to-ship combat, a special section on adding some panache to your play, and a re-evaluation of firearms combat reflective of the period."