I saw a lot of homemade edged weapons in third-world countries like Cuba. Many people do not realize that the most proliferous battle weapons in the world today are not firearms, but are still edged weapons like the one you found on the raft. Of course, their use is much more often for utility...
During my life I have acquired a few old (and very old) homemade knives. My favorite I inherited from my grandfather:
Does anyone else have a favorite rough knife?