Generations of seamen and airmen have treasured and relied upon the sextant. The purest of all nautical instruments, it enables seafarers to accurately determine their global position alone and without the aid of modern technology. Though contemporary sailors generally use electronic systems to orient themselves, the sextant is far from redundant: all commercial trading vessels are still required to keep one aboard. Should electronic systems fail, a sextant can make the difference between disaster and survival. In this invaluable tutorial for beginning navigators, Dag Pike clearly and efficiently describes the sextant, discusses its principles, and instructs in its use and care, while also outlining its practical, and sometimes forgotten, uses in coastal navigation.