One book I've wanted to put out for as long as I've worked at Paizo has been a gazetteer of different ships one could find in the Inner Sea region. Because ships are mobile, a ship of any type can be found in just about any port, opening up nearly endless options for Game Masters.
When Ships of the Inner Sea finally made it onto the production schedule instead of my wish list, I wanted to make sure that the book could serve GMs in a number of ways. The included ships, of which there are seven, range in challenge rating from foes appropriate for parties of levels ranging from 4 to 15, and are thus useful additions to all sorts of adventures. For those running the Skull & Shackles Adventure Path or otherwise using the ship-to-ship combat system presented in the Skull & Shackles Player's Guide, each ship includes statistics compatible with the system, allowing all seven vessels to be potential prey for pirate PCs prowling the Fever Sea. Each ship is fully mapped (and gorgeously so, by Jared Blando) for tactical combat and can be used as a potential PC or enemy vessel. While the crew compliment of each vessel is enough to fill a book by itself, each ship's chapter includes full statistics for its captain, one prominent crewmember, and a generic sailor or passenger stat block.
To provide more useful and general tools for GMs running nautical campaigns, we also included a chapter on sailing the Inner Sea. This includes a glossary of nautical terms, definitions of several different ship classes, and details on the region's most traveled trade routes and the hazards that make them full of adventure potential.
Three of the authors who worked on the book live or have lived on functioning boats, including naval vessels. Their knowledge of nautical terms, ship layouts and life at sea really shows in their writing, and I was very lucky to be able to get them all together for the project. It's the same reason we had Sutter write about space aliens and Wes write about Infernal contracts; you're best at writing what you know.
What I'm most excited about in this book, however, is the art. This is one beautiful book. It was really tough to pick a few pieces to show off and whet everyone's appetites, so I decided to share one piece per type: a half-page introduction, a ship portrait, and a full-body illustration. And another half-pager simply because, holy cow, is it amazing!