Here is my layout of the keel on a ply sheet. I like to use battens to make fair curves. I start with the top of the board curve and then add the desired thickness at each rib station. I space ribs at 8" on center. When the curves look good and fair, I subtract the skin thickness for the top and bottom and cut out the keel from the plywood.
Nose to tail view.
Here is the nose blocking, final shaped. When the top is installed, I'll have the finished shape of the nose and tail already, so there is no guess work or redoing the layout. Then I just have to fair the rails inbetween.
Pintail. Nice! Still need to install blocking for the fin and tail.
Using Bobby's hand plane for the bottom of the nose curve!