This is a military history with an emphasis on tactics. Sam Willis's research includes contemporary treatises on sea fighting, although he is happy to debunk myths about naval orthodoxy and illustrates his points from a wide variety of primary and secondary sources. He is intent on locating the best evidence and the most vivid examples, and for this reason he sometimes interprets “eighteenth century” rather loosely. Numerous examples from the seventeenth century appear in this book; Sir Kenelm Digby (1603–65) is quoted several times. Despite this, the book's center of gravity remains in the second half of the 1700s, with occasional ventures into later decades as warranted. For example, when he is discussing the difficult task faced by a captain who is trying to assess the intentions of an unidentified and possibly hostile vessel, Willis discusses a “friendly fire” incident from 1805 in some depth. Since the two commanders subsequently spilled a great deal of ink in an effort to justify their own conduct and save their respective careers, this exceptional paper trail offers us unusual insights into what passed for standard procedure and what sorts of guesswork and improvisation played a part in such a tense situation. The transcripts of courts-martial also form an important part of Willis's source material.

Willis is at his best when he addresses practical, nuts-and-bolts questions. The discussion of signal flags and their limitations is an excellent example. The timely receipt of a signal might be the only way to prevent collisions when ships maneuvered in close formation. Certainly, a fleet that enjoyed good communications could gain an advantage in battle. Yet there might be insufficient wind to fly the signal, or the flag itself might be too wet to unfurl properly. Captains were sometimes reduced to shouting questions across the water or just watching what the nearby ships were doing and divining their intentions accordingly. If daytime communication posed problems, what were the options at night or during inclement weather? Willis not only explains how many lanterns different types of vessel would carry and how they would use them but also stipulates the year (1690) in which lantern windows of “green plastic mica” (56) were replaced with stone-ground glass, which let more light through. There is also an interesting discussion of how lanterns were used to deceive the enemy and how specially designed night telescopes could sometimes see through this kind of subterfuge. The book's index is highly specific, so readers searching for references to lanterns, night telescopes, or a host of other topics can easily find them again.

Willis's main contention, however, is that a fleet commander in the age of sail who relied on signals alone—or expected his signals to be obeyed in a mechanical fashion—was doomed to failure. The various ships in a fleet came in different sizes and shapes; some might not even be of British manufacture, having been captured in an earlier battle. There was, then, no uniformity; each ship would respond in a different way to identical weather conditions, and each captain had to exercise considerable intelligence and initiative, even if all that was required was to keep his ship's place in line with the rest of the fleet. Willis argues that this was widely understood at the time: “Obeying orders and doing one's duty were the two parallel fundamentals of naval discipline, but for too long historians have overlooked the significance of the latter in favour of the former” (97). “Doing one's duty” meant seizing opportunities as they came up. If “a continuous and relentless push to create and then make use of transient advantage was the nature of battle at sea in the age of sail” (171), then the best fleet commanders, like Nelson, would be those who were able “to use the inevitable initiative and independence of action of his subordinates as part of his broader tactical plan” (112). This, truly, was a team of mavericks.

Willis acknowledges from the outset that his focus is almost exclusively on the Royal Navy, and the seamanship of other nations is usually brought up only as an example of clumsy technique. We do not learn about the sailors who manned the British warships, what motivated them to follow orders and fight with such alacrity, or why their training was so consistently superior to that of their counterparts in the French, Spanish, and Russian fleets. After Willis's virtuoso demonstrations of the mathematics and physics behind a ship's performance, his occasional glancing references to the human element are a bit disappointing. The problems of leadership, in this book, involve the rapport between admirals and captains, but persons of lower rank are virtually invisible. If, as Willis repeatedly suggests, the quality (and experience) of the crew was at least as important as the quality of the ship and its hardware, then a book entitled Fighting at Sea in the Eighteenth Century deserved at least a chapter on Jack Tar, the common seaman who did more than his share of the sailing, fighting, and dying.

The wealth of clarifying detail makes this a useful companion volume for anyone perusing a general history of the Royal Navy or a biography of any naval officer who served during the age of sail. As a reference work for what these ships were like, how they handled at sea, and how naval officers sought to capitalize on these material constraints for both offensive and defensive purposes, Fighting at Sea is not likely to be supplanted any time soon.