[Attrecomet]

>Oral tradition can be pretty good

That's very vague. Oral tradition was replaced by writing because writing is better, and the information content decays far slower. Do you have evidence of information transmitted orally across thousands of years? Best I know of is a few measly centuries, from the Iliad, where some passages obviously show knowledge of Late Bronze Age Mycenaean gear, but mixed up with later Archaic stuff.

>and it's not just the Black Sea that flooded, it's coastlines everywhere.

Which wasn't the specific claim here, which is "all flood myths go back to the Black Sea Deluge".

[aldonius]

> Do you have evidence of information transmitted orally across thousands of years?

Australian Aboriginal oral tradition describes flooding to create islands or bays (modern science can date the corresponding event back 7000+ years). But in certain cases the level of detail is even better [see link]:

> The story describes several named landmarks with remembered historical-cultural associations that are now underwater.

https://theconversation.com/ancient-aboriginal-stories-prese...