Oktant

Oktant is a navigational instrument used for determining the position of a vessel at sea. It is a type of sextant, which is an instrument used to measure the angle between two objects. The oktant was developed in the 18th century as an alternative to the traditional quadrant, which was used for the same purpose. The oktant is named after the octant, a unit of angular measurement equal to 45 degrees.

The oktant consists of a frame with a sighting telescope and a graduated arc. The telescope is used to sight a celestial body, such as the sun or a star, while the arc is used to measure the angle between the celestial body and the horizon. The oktant is typically used in conjunction with a nautical almanac, which provides the necessary data for calculating the vessel's position.

The oktant is a simple and reliable instrument, making it a popular choice for navigators. It is relatively inexpensive and easy to use, requiring only basic knowledge of celestial navigation. However, it is less accurate than modern electronic navigation systems and is gradually being replaced by these more advanced technologies. Despite this, the oktant remains an important tool for navigators, particularly in remote or off-grid locations where electronic navigation systems may not be available.