'A sextant can't be hacked' has become a new 'mantra' where safety and security are priorities at sea. Currently, Coast Guards and navies are beginning to bring back the art of celestial navigation.
Brass sextant from the 19th century in its box.
The sextant was used first in the mid seventeen hundreds for celestial navigation. It is used to measure the height of a heavenly body above the horizon. This is accomplished through reflecting mirriors. The distinguishing feature of the sextant is the vernier scale of 120º rather than that of the earlier Oxtant which only had a 90º range.
The Naval Marine Archive is fortunate to have a collection of various models of the sextant. The most recent donation is shown above, and dates from the nineteenth century.