As background, let me explain that I'm not new to Patrick O'Brien's work, having read all of the books several times. I've also read some literature from the period and a lot of history, and I'm a recreational sailor with a deep interest in the ships and methods of our sea-going forebears. I also assume that I have a lot to learn about most things, but not from this book!

Harbors and High Seas has a chapter dedicated to each book in the canon, consisting of a short spoiler of the plot and a couple of basic paragraphs on locations Aubrey and Maturin visit. Each contains a few maps: you'll find better ones in any atlas. There are also a few pictures, typically line drawings from historical sources. It fails because it's all so inadequate and inconsistent, and it feels as if the information was assembled over a weekend.

A few examples would help to explain this. The chapter on 'Fortune of War' contains a map of the action in which Jack Aubrey is captured by the Americans, and the track of the ships engaged. Why are there no others like this? As an example, diagrams of Aubrey's defence of the China fleet would be useful: O'Brien describes the action in detail but it is hard to follow. Similarly, how about a chart of Aubrey's last action in the Phalarope? It's not beyond my ken to construct a diagram of the fictional location from O'Brien's text, but it would be nice if this book saved me the trouble.

It's not just the maps that are inadequate, it's the text as well. There's simply too little 'meat' in it. I'd at least expect some decents insights into the conditions and difficulties of navigation under sail in the Thames, the Baltic, and around the Horn, to select a few examples.

There is so much that could have been included, but it would need more effort and research to do so. Instead the result feels as if it's cobbled together out of some basic notes and a few pictures.

You'll get more satisfaction from finding your own insights than you will from this book.

Its author, Dean King, covers all twenty of the Aubrey-Maturin novels, one by one and in order, providing historical background which helps explain the backdrop against which the stories take place, as well as maps and contemporary illustrations detailing the voyages, actions and places described in them.

The plot of each book is also summarised (without giving away too much of the endings), which makes this a handy way of catching up if you've not read previous novels in the series (or if, like me, you just have a sieve for a brain).

It's an enjoyable and informative way of placing the Aubrey-Maturin series in its historical and geographical context, and also serves to show just how credible and true-to-life the world of Patrick O'Brian really is. If there's one criticism, it's that there isn't enough detail - but readers hungry for a more technical look at O'Brian's naval world can address that need with "A Sea of Words", by the same author.

Highly recommended.