I built a Kaholo last year and had the same thoughts but ultimately didn't add much re-enforcment other than an extra strip of glass.  Now that I've used the board in both fresh and salt water I have contemplated  putting a rub strip on the bow.  It's the most scratched area on my board (but it still looks really good).

I was paddling in the inter-coastal on NC and dodged oyster beds (they are like groups of razor blades).  They had me thinking I should have used graphite for the entire hull!

A rub strip on the bow and perhaps some on the fins.  I'm more of an explorer and adventure paddler and not looking for weight reduction and racing.  Plus I let all the kids and grown up kids use the board.  So far, the board has held up well.  The boards are designed pretty solid and don't need much re-enforcement in my opinion.

   Thanks Tim. I like the rubrail idea, I'll see what I can find at a local marine store. My initital plan was to do the whole hull in graphite but decided against it as I really like the look of wood. I figure if the hull ends up getting banged up it will only be a couple days work to strip the varnish and graphite the hull. I agree about the solid design, there was 250+ pounds of weight holding the deck to the hull while gluing it down and I did not notice any flexing of the hull.