Use a sponge to soak up concrete mix in whatever shape you desire and let it harden into a hardened version of what you just cut out! Pavers or garden accents? (I would wear rubber gloves while dipping/soaking!) Worth a try.
There will be lots of driftwood waiting for you here in the Puget Sound area if you decide to come back and to do a little more sailing this summer. Description from whitegunpowder.com. I searched for this on bing.com/images