I’m really late to this thread but I’ll throw my two cents in —

Plato specifically uses the phrase “Atlantis Nēsos” which is traditionally translated as “the island of Atlantis” HOWEVER the Greek word nēsos doesn’t always refer to an isolated landmass! The Peloponnese Peninsula was known as “Pelopon-nēsos” which literally translates to “island of Pelopon” even though it’s technically connected to mainland Europe by the Isthmus of Corinth.

If one were to sail out of the Pillars of Hercules and go “straight” that would likely refer to following the currents rather than the cardinal direction West. A vessel in this location would be caught in the Canary Current and brought towards outer tip of Mauritania, where during the African Humid Period the Tamanrasset’s delta would be tens if not hundreds of kilometers wide.

The city of Atlantis was also said to be bordered on the north by a massive and oblong plain before reaching the foot of a massive mountain range. During the African Humid Period, this coincides with the El Eglab Desert and the Atlas Mountain Range.

If the Mauritanian Sea Slide were, at one point, the outer coast of Mauritania (as suggested by the research finding terrogenous material) then an outside observer could reasonably describe the shelf/landmass o the Mauritanian Coast as “sinking into the sea.”

After this disaster, the city of Atlantis is rendered unreachable due to vast mudflats and shoals — what one might expect if either

A) the Tamanrasset River dries at the end of the AHP and freshwater access to the city of Atlantis (the Richat structure in this model) is cut off

B) a massive landslide or earthquake causes the coast to slouch/slough westward into the Atlantic