Since 1940, Mixter's Primer of Navigation has been the most relied-upon guide for sailors and boaters throughout the world. Within three years of its original publication, the book went through fifteen printings; in 1943 the second edition appeared and was followed by seven reprintings. In the early 1940s, the text was widely used as the primary resource in the training of navigators for service in World War II. After the war, when pleasure sailing and boating became an increasingly popular pastime, Primer of Navigation found a new audience of readers eager to ensure their families and friends of safe, pleasurable, bluewater adventures. Herrold Headley has now prepared a completely revised and updated seventh edition reflecting the latest developments in the art and science of navigation including vital new information on precise positioning and communication by electronic means; both Loran C and advancements in high-frequency FM and single side band radio telephone communications systems are covered in.