Two Flood stories The Kolbrin contains, not one, but two versions of the worldwide Flood story, one in the Egyptian Book of Gleanings and one in the Celtic Book of Origins. In a veritable ocean of flood myths, why do these two stand out?*
The Deluge story in the Egyptian Book of Gleanings The names in this Kolbrin versioniv suggest an ancient Sumerian source; it indicates when the Flood took place, where the Ark was built and where it came to rest, giving more circumstantial detail than the poetic Atrahasisv and Gilgameshvi epics or the clipped Genesisvii prose version. Above all, it says loud and clear what caused the Great Flood – something no other written account does – and explains why human beings have forgotten the more important aspects of an event which by rights should be standing firmly at the centre of world knowledge, not mouldering away on the dusty bookshelf of myth.*
*The Floodtale in the Celtic Book of Origins The second version of the Flood storyviii came to Britain as an oral retelling and was written down between the first and fifth centuries ADix. It was brought by a ‘far-ranging race from Krowkasis [the Caucasusx], the Motherland where Gatuma ruled, where sky-reaching mountains rise out of a wide, green, dark-soiled plain. They were horse-fighters, known among themselves as the Wildland Cultivators… It was the Wildland Cultivators who gave the flood-tale to our housebuilding forebears, but the generation of its happening is lost.’ What makes this story special is that it reveals there was not one Ark, but two. More on this later.
https://grahamhancock.com/whitemany11/
There's an excellent JRE with Graham Hancock and Randall Carlson discussing exactly this!