I think it has to do with the celestial sphere...the map of the night sky. There is a pole star in the Northern Hemisphere, Polaris, and although not spectacularly bright, it's pretty close to the celestial North Pole. That meant for early maritime navigators, if you left western Europe, and set sail Westward, you only had to keep the Pole Star at the same height above the horizon, to maintain a path of equal latitude. That meant, if you sailed to the Azores, you could return to your point of departure by reversing course, and keeping the pole star off the port side, at the same height above the horizon.
Not so in the Southern Hemisphere, where no distinct pole star was used. So, when mapmakers put their maps on a globe, the Northern hemisphere's trade routes located destinations at equal lines of latitude. Christopher Columbus is said to have carried the Piri Reis map that included the Easternmost points of Brazil, Columbus having been shipwrecked off a Portuguese village and recovered in the family of a mapmaker. Similar technique worked in the Mediterranean. Knowing the night sky, in clear weather, is a good skill for outdoors people, for when your tech stuff goes down. (I am at a loss for how some 2500 people a year disappear in Alaska)
Piri map SEE:
https://en.wikipedia.org/wiki/Piri_Reis_map
pete