Whether or not you're a rabid fan of Patrick O'Brian's Aubrey and Maturin series of Age of Sail novels, Dean King's A Sea of Words is a must-have for fans of the nautical era.

King's lexicon is an in-depth dictionary specific to the many terms used in O'Brian's books, as well as the real people and places who appear in those pages.

Even better is a pair of essays, which provide keen insight into the period.

The first, by John B. Hattendorf, describes in great detail the basics of shipboard life, the chain of command from the seat of the Admiralty in London to the smallest naval ketch, basic tactics and the size of the navy over the years in question. Hattendorf, briefly but thoroughly, outlines the chronology of events during Britain's pertinent wars with France. This essay, in particular, is useful for anyone not intimately familiar with the ins and outs of the British navy.

Next, J. Worth Estes explores the concepts of naval surgery and medicine as employed by Stephen Maturin and other of his profession in ships where disease and accidents sent more men to the orlop deck than any number of cannonballs. Estes opens up the naval medicine cabinet, explores the common treatments and procedures, and discusses the merits or failures of various techniques.

The book also includes a helpful series of illustrations of various types of ships, maps of areas where major battles took place, and charts showing specifics of a ship's decks, sails and rigging.

The lexicon itself spans "aback" to "zephyr" and includes definitions of naval and medical terms, literary references used in O'Brian's work, food and drink served at Aubrey's table, key historical figures, foreign words that appear in the text, flora and fauna described through Maturin's passion for natural history, and more.

A Sea of Words is easy to use, easy to read and endlessly helpful. I will keep it handy, in a prominent place in my collection, for convenient reference.