: 2) The second area of weakness would be the mid span of the cockpit. Most
: canoes have a brace (thwart) there. That would keep the cockpit from
: cracking-in from a severe blow broadside. I may add some sort of removable
: thwart device and I have ports along the inside cockpit for doing that
: type of thing, see
: http://www.chipsandresky.com/cedarstrip/images/inside.jpg

Rather than a removeable thwart consider a rigid ( but removable and/or repoitionable) mount for the seat backs for both paddlers. The problem is not so much a sharp blow to the middle of the boat, but rather the water pressure on the outside of the boat wanting to crush in the long sides of the boat. The thwart(s) resist that pressure. It is not a big concern with a lightly loaded boat, but the pressure increases as the boat is loaded and sinks down in the water.

PGJ