Thanks Wiz-Nerd. Circumnavigation of Africa is attested in ancient texts, and reportedly took two years. Tarshish (when equated with Tartessos) wasn't in Spain as often claimed (and neither was Tartessos), but referred to Crete. To reach Crete from Ezion-Geber meant circumnavigation of Africa.
Circumnavigation of the Earth was probably not tried until the Age of Sail, although the oceans have never been the insurmountable barrier as believed by the landlubbers who seem to scrawl all the Clovis-First-and-Only rubbish.
The striking thing to me is that like the Nazca lines
this “message” can only be read from the air or perhaps
some elevated point in which case the letters would have
to have been distorted to compensate for the fore shortening.
Are the markings stretched out in any way?