> From what I've seen you can't bend a panel to a fair curve with a butt
> joint, you will always get a flat spot at the butt joint. So a boat that
> uses butt joints will either have flat spots or the design must be such
> that the joints occur where the panels can be butted at zero degrees. that
> would seem to restrict designs to 16 foot lengths and a symetric form.
> That all said it is not easy to get a good scarf in 1/8 plywood. I cut
> mine on a table saw with a homemade jig and it is difficult to get the
> feathered edge with out splintering.

And yet, I have a Pygmy kit that uses butt joins on 4mm plywood, with NO flat spots, and the joints are NOT at places with zero degree curves, and it is a 17.5 foot boat. Hmmmm. Scarfing is not too difficult, if you're willing to take your time and keep your block plane sharp. I would tend to agree with Pygmy's assessment that for kits, with pre-cut panels, it's easier to use butt joints, and for plans, where you'll join the plywood BEFORE cutting your panels, that you may want to use scarfs there, if you're comfortable with doing them, or have an expensive scarfing jig, since it will be easier to cut accurate panels then.

Chris