Somehow I doubt that the ancients knew how the earth looked from above in the first place. Lets start from there.
Now how can they compare something they did not know about with something they saw in the sky?
They simply did not have the technology to travel significant distances and map this accordingly in the process. As far as I know paper and writing were not invented - so even in the unlikely case that generations of shamans have documented little bits of coast and creating some kind of large scale map from that, it all becomes very difficult, innacurate and unlikely.
Now what I can think of if I really go way out on this, is that the stoneage people did actually map stars to geographical features of a smaller magnitude - e.g. something that could be described or scribbled in sand or on rock, e.g. the scale of a few kilometers perhaps even more.
This by no means is compareable to oceans, seas and complete continents.