The plan is to build the boat using 1″ thick EPS (expanded polystyrene) foam with fiberglass and epoxy on the inside and outside. The advantages are: EPS is easy to work with, the hull will have good impact resistance, the EPS will provide flotation, and it is lightweight. The disadvantage is I am having difficulty finding high density EPS. I’ve previously used EPS with a density of 4lbs. per cubic ft., but the suppliers I used are no longer in business. I’ve searched all over the SF Bay Area and the highest density EPS I can find is 2lbs. per cubic ft. For reference, Douglas fir is about 33 lbs. per cubic ft., and steel is about 490lbs. per cubic ft.
The problem with the low density EPS is it’s more difficult to shape, doesn’t allow as fine a finish, and doesn’t have good impact resistance. The fiberglass will delaminate from the EPS where there is high stress, and this will weaken the boat. So I really need to find high density EPS, and that is what is holding me up right now.
You will notice that the sailing canoe does not have a canoe stern. This helps to reduce the length, and makes it easier to mount the rudder and controls. The downside is increased drag when the stern is buried.
The round thing on the starboard side of the rudder in the top view is windvane self steering for which I have not completed the design. It may not make it into the final product. The rudder can be raised and lowered from inside the pilothouse, and steering is controlled by lines leading to the pilothouse as well.
The double hidden lines ahead of and behind the pilothouse are bulkheads. In front of the forward bulkhead is where my bike will be stowed, along with anchors and other gear and supplies. Lighter gear and supplies can be stored behind the rear bulkhead. These compartments will be watertight and isolated from the main compartment. The main compartment is almost 7′ long, so I can sleep in there (at least in theory). there is also headroom to sit upright.
The one issue I am still not completely convinced will work is stability. The height to the top of the pilothouse is greater than the beam. The idea is to keep the weight, and thus the center of gravity, as low as possible so the vessel will wobble and even tip, but will pop back up. But I’m not sure that in practice I can get the weight low enough. With flat sides there is going to be a tendency for the boat to want to lay on its side if the center of gravity gets too high. If this is indeed a problem, plan B is to attach inflatable tubes to the sides of the pilothouse so it can never roll all the way onto its side.
I believe that covers the design with the exception of the rig, which I will discuss next time.