I will be upfront and say that I have not completely read the NG site and all the postings. I will read it as I get time. and as for wikipedia - well, I just won't go there. I have some bias (not positive) about wikipedia and anything that has anything to do with "Biblical issues" and information.
So take my comments with a grain of salt, or well, maybe a salt-lick if that's necessary

There are many flood stories and myths in just about every culture. One of the things I personally have had to discuss with some is that there is an apriori that says that the Genesis account(s?) are based on "earlier" accounts, and specifically the Gilgamesh Epic and the Atrahasis Epic.
that paradigm comes from authors that say things like:
"It is clear that Hebrew tradition must have received its material from some intermediate … source, and that it proceeded to adjust the data to its own needs and concepts." - E.A. Speiser, Genesis (1960s?)
My thought is initially that the accounts may have been available at the times of the writing of Genesis, but why the assumption that those accounts were used as "sources" and modified to fit the Genesis account.
I submit that the accounts WERE available, not simply because therer were many flood stories, but because there was a prevalent one, that was oral and had not been written by Hebraic authors yet. in other words, the "story" of the Genesis account was the original, but the Mesopotamian authors did the changing of the tradition to suit their current mindset and understanding of the Gods.
Do I have proof? of course not, but that doesn't' mean I can't believe it (until proven incorrect).
but back to the black sea area floods. is this even the right place to look? shouldn't the evidences of catastrophic flooding be more in Northern Mesopotamia? Are we talking about the area of the mountains of Ararat, or Mt. Ararat? I am not expert, but the entire range is a very large area, and more "Biblical" (assuming the Biblical reference is "historical" - which may or may not be an assumption held by all, I suppose).
just my limited-trained opinion.