Very early settlers of North America had at least some ability to make water-crossings, since there is evidence of early human activity on the Channel Islands off California (Santa Rosa, for example). But by the time they crossed the continent and reached the Gulf Coast, those traditions had decayed and had to be re-invented: the islands of the Caribbean were not settled until several thousand years later. There were various odd animals on some of those islands, for example ground sloths the size of a bear. They did not go extinct at the same time as the large animals on the mainland: they waited for people to show up and then kicked the bucket. Which is odd if you think that climate change or an impact caused those mainland extinctions.
When humans did arrive, they seem to have started in Trinidad (very close to the South American coast) and moved up the Lesser Antilles. This seems to have happened repeatedly with successive waves of invaders, the last being the Caribs.
This suggests that a chain of islands with fairly small separations is a good recipe for developing your maritime capabilities, and maybe that was the case for the road that started with Bali and continued on to Sahul and the Solomon islands, back in the day.