I guess I'm still stuck in the land-bridge school of thought. Very interesting. I've read much about seaborn contact between Asiatic peoples and New World peoples as well as pre-Columbian contact between the Old World and New World. The presumption was always that the New World peoples came hwere via land migration
On the other hand, Eskimos didn't wait on the Land-Bridge when they decided to move into the Arctic, and the Haida in the PAC NW were building quite large seagoing vessels all along.
Thor Hyerdahl sought to dispel the primacy of the Land Bridge theory by building reed boats and balsa catamarans to cross open ocean. I would have loved to have sailed with him.