Answer :
With inventions like the astrolabe, explorers could better calculate where they were. By calculating they could better know their latitude and location on a map. Improvements on the magnetic compass also helped explorers to keep from getting lost on land or sea. Improvements in cartography (map-making) and the creation of the printing press made the maps look much more uniform and closer to what we see today in satellite images. Improved ship design also allowed explorers to sail further and faster. They also started to understand currents.