Description By inventing ways to travel on water, people have been able to see and trade with new lands, conquer new territories, fight great sea battles and enjoy new sports. This book will help you to understand why ships have played such an important part in human history. With the aid of cross-section illustrations and simple experiments to do at home, you will discover how vessels stay afloat, how a sail works, what keeps a submarine underwater, how a hovercraft skims on air, the elements of navigation, and much more.