"Harbors and High Seas" is a glossy and well-written publication that is invaluable in guiding the amateur O'Brian reader through the various adventures of "Lucky" Jack Aubrey and his ever-faithful companion Stephen Maturin.
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.