What are the historical roots of ocean exploration?

    Charting maps has been around for many years. The Greeks and the Romans used navigation through looking at stars and navigating through the north star. Then after a while they started drawing maps using the north star and the stars around it. Then in the 1700's they started  to map the ocean by using the land and a compass invented by the Chinese. John Harrison invented the chronometer which helped to tell time. It was the first clock that was able to be brought aboard a ship and help people to arrive at the right time. And they could navigate the longitude and latitude. Years later the GPS was invented to navigate the ocean and it tides and wave height and strength. 

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