>>2694467In the Northern hemisphere, navigators usually used Polaris. Using a sextant, they measured the angle between Polaris and the horizon. The angle would be very close to the latitude of their current position.
In the Southern hemisphere, they did the same thing but with the south celestial pole. The problem is that there’s no bright star close to the south celestial pole, unlike Polaris in the North. So, they used the nearby Crux and Pointer stars to determine the approximate location of the south celestial pole. The angle between the south celestial pole and the horizon is the same as the latitude of the observer.
