After my recent adventure, I must admit to a certain nostalgia for my wingsails. They were easier to handle, and a fan-up was impossible!

The components were left in the custody of David Thatcher in NZ, and I told him that if he got tired of them cluttering his yard, he could take them and sell them for scrap. The first thing we have to do, then, is to ask him if they are still with him.

The mizzen wishbones are suited to a chord of 3600mm, and the mainsail's wishbones are suited to a chord of 4500mm (measured over the flat sail, luff to leech). I spaced them vertically at 1300mm. Either could give you somewhere close to the area you need, but if you used the mizzen wishbones, you would have to go for a high aspect ratio rig. I see that your boat is 27ft long, and looks fairly stiff. I'm not sure which size of wishbone I would choose.