This slim volume is very attractively put together. The layout is pleasing, and the many photos and historical paintings are easily the best part of the book. Past that, though, the quality drops off.
The text is reasonably well written, but doesn't always flow well. Often you'll turn the page and be surprised that the chapter is over. Or you'll read fairly detailed information on one subject, yet find gaps in others. For instance, there is a detailed chart of the actual weight of cannon shot depending on the nationality of its manufacture. This is interesting, but seems oddly out of place. In many places the book feels like a hastily organized jumble of facts. A bit more effort, and the services of a decent editor, would have improved this book.
Another improvement that could have been made by an editor is the removal of numerous typos and glitches. On one page, two illustrations have their captions transposed. In many other places obvious typos are present. If I can catch them by reading the book once, they shouldn't be there.
Perhaps the worst flaw of this book is its incompleteness. It's missing a serious discussion of how ships were sailed, information on battle tactics, and recurring locales from the novels. Worse, the book uses terms that it never explains. For instance, the caption of one illustration mentions that the bowsprit gammoning is ommitted for clarity. But gammoning is not in the glossary. (As it turns out, if you google for "bowsprit gammoning" you'll find an amazing online reference, geared towards model ship builders, with more detail than you can shake a stick at) The book is filled with such omissions. I'm pretty familiar with nautical terminology, but I'd worry for someone who got this book as their only reference.
Overall, I enjoyed the book; I received it as a gift and am happy with it. The numerous contemporary illustrations and photos of actual items are a joy, and the book did contain facts that I had not previously been aware of. However, as a reference book, it is somewhat lacking.