Sextant Image and Operation


A sextant is used to make observations of the sun and other celestial bodies in order to determine a boat's current position. The navigator sights the sun through the sextant's telescope and, by moving the index arm, aligns the image of the sun with the horizon. The sextant then establishes the angle of the sun above the horizon. By knowing the date and time of day that this angle was recorded, the navigator can calculate position.