There she is in what is most likely her final form. The tube flexed too much so I went with plywood 'wings' for stem caps. The tube does not inflate uniformly so I made duct tape bands to try to limit expansion. She's comfortable, I can reach everything from the cockpit.
We later did some sea trials on the Corky. Winds were 6-8. We were able to make ~10-15° against the wind on one tack, but not the other. Rick suggested trying an oversized rudder. That'll be tested.
Tack and windward progress. Not much - no more than 10° or so, bit progress.
I was able to do some more Corky testing today, but I was alone at the local scum pond ('alone' as in 'alone but for the hobos') and screwed up my GPS so didn't get and records of readings.
Wind was best yet: Nearing 10mph most of the time, but at least in a constant direction. My foils are made from 1x10s: Daggerboard has 24" wetted surface, rudder has 12" wetted. Sail is a 16sqft Balanced Lug. (you've seen the pictures)
I could barely claw to windward, maybe 5°, but it was forward progress. I did 5 pairs of tacks across the pond and made ground on each.
It doesn't really produce a wake. When pinching hard, the bow would start to go under (you can't really scotch back very far to try and balance it) but there wasn't a V shaped wake in my trail.
Speed was between 1 and 2mph, when pinching, best possible was 1.1. Running downwind, I touched 2.2 twice. Best guess at average will be something like 1.3 or 1.4.