By any chance did you read Graham Hancock’s book “Underworld”? He addresses the inundation of very early civilization coastal sites at the end of the last great ice age.
Yes. But I also looked into other sources such as marine archeology.
Marine archeology is in its infancy. The British are searching close to home, exploring areas under the Channel. For years and years fishermen have been hauling in, not only fish, but the bones of long extinct animals, mostly wooly mammoth. The discovery of an ancient village off the east coast of Cornwall has been interesting for what it reveals of neolithic people living in that area.
The discovery on the Black Sea floor of ruins from 7500 bc has been a revelation for many, for it happened at a time when the sea level then appears to have been 15 to 20 feet higher that today’s sea level. This flood into what had been known at the time as the Euxine Lake, soon to be known as the New Euxine Sea by the ancient peoples around the Mediterranean, set into motion an exodus of people rippling outward in many directions. The ‘Old’ Euxine Lake, in now appears, was the original home of the ancient Celts.