With over two-thirds of the globe covered by water, the ability to navigate safely and quickly across the oceans has been crucial throughout human history. As seafarers attempted longer and longer voyages from the sixteenth century onwards in search of profit and new lands, the tools of navigation became ever more sophisticated. The development of instruments over the last five hundred years has seen some revolutionary changes, spurred on by the threat of disaster at sea and the possibility of huge rewards from successful voyages. As this book shows, the solution of the infamous longitude problem, the extraordinary impact of satellite positioning, and other advances in navigation have successfully brought together seafarers, artisans, and scientists in search of better ways of getting from A to B and back again.