There is one piece of evidence that absolutely proves that there was no advanced sea-faring society in the america's.
Tobacco, or actualy the lack of it in the old world. Tobacco is native to the carribean and to cuba in particular.
If there had been a ocean going trade based society in the carribean, they certainly would have spread their tobacco every where they went.
It only took a couple of visits to the carribean for the Europeans to bring it back to europe.
I personaly believe that there was a very early sea faring society, maybe even as far back as the time period in question.
But it was not in the americas or europe, but in south east asia.
There are very intriguing archealogical "anomolies" that have yet to be fully studied or explained.
The Yanoguni find is very interesting, if it proves to be man made then it will re-write human history.
And while most of the rest of the world was still hunter-gatherers, they were plying the coastal waters of the pacific and indian oceans.
There are some interesting cutural commonalities around the world that raise some questions.
I'll continue later.