Originally Posted by SailingStNick
I would go with this explanation. Also, that the oceans have been terribly overfished.
And, yes, I think the crew of KonTiki used freshly cut Balsa, which absorbed water over time and made the raft even slower. I also recall that they observed one of the first Whale Sharks seen by man.
EDIT: I WANNA GO!!!!!
Thank you, I thought I wasn't FADdish enough with my acronyms for my answer to be appreciated.
You are right, the logs slowly sank, but I think they felt that seasoned logs would sink even faster, that the sap kept the water out longer. I'm guessing that as the sap leached out it could provide nutrients to micro flora.
No copper paint either. I'm imagining the bottom of the raft looking like the Sargasso Sea at journey's end.