Depends on how rocky the river is, how much weight you can tolerate, and your
definition of inexpensive.
If you plan to bump rocks a lot, the drift boat solution of cladding the bottom
with a tough plastic such as HDPE or UHMW might be warranted. Not light and not
real cheap.
Next less extreme would be glass in epoxy. A little graphite in the epoxy will
reduce friction on rocks and toughen the epoxy a bit.

Have you asked the designer? He's just full of clever ideas.


Andrew Butchart wrote:

I'm currently working on a Phil Bolger designed plywood sailing pirogue (the
CSD one). Even though the original design calls for a lee-board, I can't
leave well enough alone and am planning on an off-centre centre-board.

My question is about protecting the hull bottom at the centre board slot.
On previous boats (with a dagger-board), I just added some fibreglass tape
around and overlapping the slot, but I was wondering for this one if perhaps
some sort of shoe would be appropriate, and if so what (inexpensive and easy
to find) materials might be suitable. I'm intending on using this boat in
locations where I will have to paddle up a rocky river to a sailable lake.

Thanks

--
Andrew Butchart

http://www.floatingbear.ca