Davis Mark 3 Sextant

A forerunner of this instrument was developed for emergency use during WWII, called the "Lifeboat Sextant." This is the least expensive sextant in the world that will provide dependable accuracy adequate for actual ocean navigation. With good procedures you can obtain some 5 to 10 miles position accuracy routinely, and better with practice, providing you follow the careful procedures outlined in the book above, which is also included in our cel nav course materials. All replacement parts (even the screws!) are readily available. Note that there are no optics nor telescope and the vernier can only be read to the nearest 2', so obviously one needs to take multiple sights and average them to obtain good LOPs and the fixes themselves must be made from 3 bodies properly selected. This sextant is popular as a back-up or learning sextant, but aside from these celestial applications, it is actually the sextant of choice for inland and coastal piloting. Using the sextant horizontally, you can find your position on a chart much more accurately than you can by other conventional piloting techniques such as compass bearing fixes.