Archaeo,
I accept your statement, but for there to be no evidence there was this awareness and plenty of evidence there wasn't accurate awareness.
All of the oldest maps are well off in latitudes, with frequent mistakes in longitudes. This is explainable only by allowing for distortion from both horizontal viewing and inaccurate time of travel estimates.
These were all corrected by the invention of accurate sea-borne clocks.
So we are asked to assume all the inaccurate maps were deliberate smokescreens to hide their advanced knowledge?
Possibly created by cartographers who weren't on the aliens "most favored sentient being" list?
I am a fully disclosed amateur, make no bones about it. But very well versed in sea travel and travails. I know the approximate introduction time of major innovations, and their impact on seaborne travel.
His entire theory flies in the face of everything I know about this part of history.
Even the admittedly fabulous Antikythera mechanism had real limitations in placing one's position on the earth without excellent observations and knowledge of local terrain.
Jammer