A handy, splash-proof, on-the-water summary of the key things you need to know about navigation at sea: the perfect quick reference guide to keep onboard. The book covers all the navigation essentials: charts, compass, tides, standard and secondary ports, dead reckoning, estimated position, course to steer, lights, GPS, waypoints and buoyage in a highly illustrated format making it easy to understand at a glance - ideal for those moments when you need an answer, and you need it fast! Spiral bound, this little companion stands up to frequent use and serves as a great aide-memoire.