We will probably never find boat artifacts that can prove this one way or the other.
From memory, the oldest identifiable boats are less than 3,000 years old.
Also, the Pacific coast of western North America 10,000-20,000 years ago has been under water for thousands of years after the glaciers melted, which has wiped out almost every trace of human artifacts.
The boats don't have to be found to know that they were there. Flores Island has 800,000 year old artifacts, and during that interval there's never been a land link to the mainland.
Regardless, the oldest craft currently known is the 10,000 year old Pesse canoe.