Titanic Memorabilia Brass Sextant-White Star Line-Solid Brass Sextant.This decorative sextant is a Beautiful Gift for Titanic lovers” A sextant is an instrument that measures the angle between two objects that are visible. Primarily, it is used to measure the angle between a celestial body and the horizon, a process normally known as sighting the object or taking a sight. The angle measured and the time at which it was measured is then used to identify the location of the user on the grid map of the world. Thus sextants are basically navigational tools and have been successfully used by seaman and even other travelers over the years. The most common process of this is to sight the sun at noon to find the latitude of one’s location.