> Appreciate the input. Now if we were to look at a birds eye view of the
> boat the bow right, the stern left; this joint runs crosswise, dead-center
> of the boat. It runs down the port-side, across the bottom, up the
> starboard side. It seems to me it'll be a hinge, epoxy or not. Details:
> I'm building with 3/8" Mahogany marine quality plywood. I chose
> 3/8" for it was the thinnest 5-ply available. I'll S&G the sides to
> the bottom, and fiberglass the lot. The cross-section will be a square-U,
> very little rounding (I don't see me developing curve cut panels that will
> match). The hull will be flat from stern to mid-section then curve upward
> to the prow about 6-8"; and there'll be a transom.

> Here, in Hawaii, the boat is going to sea. Until I've built up confidence
> in its structural integrity it won't go far to sea. Still there will be
> some wave jumping. A Hawaiian racing canoe's hull is made of 1/2-3/4"
> thick fiberglass. It is a U shape and one continual form. Mine is plywood
> and joined as above. A fiberglass canoe jumped a wave recently (outbound)
> until the stern alone was in the wave, the rest airborne. When it hit the
> backside of the wave it blew a hole through the bottom of the U.

> I don't plan on a lot of wave jumping, but it is often unavoidable. You
> can see my consternation with this joint being centered and acting as a
> "hinge" upon impact. Any advice on support ribbing, etc. running
> longitudinally with the hull and perpendicular to the joint that may help.

> Mike, how should I go about offsetting the joints? Scarf joint full sheets
> of plywood then cut diagonally across it? Hmmm...hadn't thought of that;
> I'm very longitudinally focused I guess. Would that be the best way?

> Thanks again gentlemen.

If the hull and sides are basically flat I'd back the joints instead of offsetting them. But you could offset them by scarfing on the diagonal or putting an extra joint in your middle panel so that the scarfs end up 4' away from each other. It's more work but it eliminates on joint across the whole boat.

Mike