A lot of little details got tweaked in the process of presenting the various aspects of this design and taking in all the suggestions that came back. The draft (with the appendages up) got even shallower; it is now down to just two feet. The construction technique changed from the original plan, from very a adventurous combination of concrete/plywood/fiberglass to very conventional, proven glue&screw fiberglass-clad plywood core. The bottom acquired copper cladding. Headroom in the pilot house got boosted to six feet (it is, after all, a houseboat, so anything less than six feet of headroom throughout would be simply unacceptable). It acquired gunwales with scuppers, deck beams, and a large raised hatch/skylight in the middle of the deck with boom gallows right above for hoisting cargo in and out of the cabin.
The next phase is to enter the sketches into CAD, and after that will come a scale model, epoxied together out of thin plywood forms milled out on an NC machine, to do stability and towing tests, and to figure out the exact weight and placement of ballast. I might even splurge on an RC set and, since I'll be back in Boston, try sailing it around the dedicated model sailboat testing pool on the Esplanade. My goal is to draw up a full set of drawings together with a set of NC mill paths for the plywood pieces.
After any final comments, this blog is going to sleep until further notice. Since I will announce any new developments right here, please sign up to receive them. It's been fun, and very useful. Thank you all for your comments.