: A buddy and I wanted a folding canoe some years back, We set a
: target of 15 minutes for the first time with two of us, assuming
: one person would get down to ten minutes with practice. We never
: got close on the four different boats tried. Some required too
: much affort; we are somewhat elderly and I had problems with
: arthritis back then; the need for scrabbling around on the
: ground didn’t help. Most of them we would have left assembled
: and knocked down for Winter storage, which is not a sufficient
: advantage to justify the extra cost and weight.

I agree. If it's a quick and easy assembly, it will get lots of daily use in a variety of situations.
If it's slow and difficult to assemble, it's a PITA and won't be used unless absolutely necessary.

: I looked at designing one myself, considered several systems, the
: best approach I came up with was like your plan “A” but I
: couldn’t figure out a workable design. I didn’t think my
: needlework skills were up to making a PVC envelope so the
: bag-over-a-frame approach was out for me.

The problem with Plan A was that when the boat is assembled, the shape of the "bottom plates" of the hull mate
perfectly to the "top plates" of the hull where they are joined at the chine like an S&G kayak as the sections
assume the curve.

However, when folded / lying flat as a panel, the bottom plates at the chine are extremely curved at it's chine,
and the top panel is still quite straight at it's chine connection to the lower panels. This causes problems when
trying to a hinge along the panels due to the 8.7" wide gap that needs to bridged with PVC hinges along the chine
line between panels.

Here's a drawing of the panels when attached, and one with the panels lying flat / as when folded lengthwise.
This large gap issue can be overcome, partly by the flex associated with 2" wide PVC hinges that span the gap
between the 3 X 4ft panels top and bottom that make up the 12ft boat length. What's left has to be overcome by
removing some plywood from the bottom panels, though this creates a loose fit between top and bottom hull panels
that must be overcome by the hull bottom skin filling the gap.

The simple solution is Plan B with it's PVC bottom skin.

Simple is good :) ... Tom