Perhaps the earliest version of the Noah’s Ark story/myth/history doesn’t describe a ship at all – but rather an underground shelter, as protection from a heavy winter?

(Ancient Zoroastrianism text) Avesta:

And Yima did as Ahura Mazda wished; he crushed the earth with a stamp of his heel, he kneaded it with his hands, as the potter does when kneading the potter’s clay.

And Yima made a Vara [enclosure], long as a riding-ground on every side of the square. There he brought the seeds of sheep and oxen, of men, of dogs, of birds, and of red blazing fires. He made a Vara, long as a riding-ground on every side of the square, to be an abode for men; a Vara, long as a riding-ground on every side of the square, for oxen and sheep.

…All those seeds he brought, two of every kind, to be kept inexhaustible there, so long as those men shall stay in the Vara.