3-14.

Horror. Averted. No need to make a trip to Panama City, and looks like our centerboard will be strong even though it's in a couple pieces. We were able to get most of the second half in one large piece with only a small, long cutout. Made the missing piece by tracing with paper - this paper model method works really well. And in the process we created a roadrunner scrap! Yet, this will potentially also be cut up to use for other parts.
Today we also cut out a few more notches that were invisible on the designs and began making the 20x20mm doublers that will be attached to each frame, the bottom rails and the seat top supports that the bottom and seat planks will be attached to. The bottom rails and seat top supports are at slight curves, so we used clamps to hold the wood along the desired curve, then pre-drilled at 100mm (approximate) intervals. Screws will be countersunk, connecting the 20x20 softwood strips to the plywood. Got to use the new drill/screwdriver a bunch - it works well and is nice and lightweight.
Shadow read the plans to us - she understands them about as well as we do most of the time.