Somehow I missed seeing this post last year. I just stumbled on it today or i certainly would have replied. I was on Marsh and ran Jerry's (AKA Carvedog's) boat through dagger.
I do not remember talking about an oar blade or saying no guarantees. My friend Kieth Pearen, (Pearen) was out there a few days later than me and is known to run other people's boats through dagger for them. He just wrote aTR about a 36 hour marsh to main trip.