Book excerpt: Our understanding of warfare at sea in the eighteenth century has always been divorced from the practical realities of fighting at sea under sail; our knowledge of tactics is largely based upon the ideas of contemporary theorists rather than practitioners] who knew little of the realities of sailing warfare, and our knowledge of command is similarly flawed. In this book the author presents new evidence from contemporary sources that overturns many old assumptions and introduces a host of new ideas. In a series of thematic chapters, following the rough chronology of a sea fight from initial contact to damage repair, the author offers a dramatic interpretation of fighting at sea in the eighteenth century, and explains in greater depth than ever before how and why sea battles (including Trafalgar) were won and lost in the great Age of Sail. He explains in detail how two ships or fleets identified each other to be enemies; how and why they manoeuvred for battle; how a commander communicated his ideas, and how and why his subordinates acted in the way that they did. SAM WILLIS has lectured at Bristol University and at the National Maritime Museum in Greenwich. He is also the author of Fighting Ships, 1750-1850(Quercus).