Quarter knees are cut. For the stern knees I started with this hunk:
which is a nice dense piece of fir I picked up somewhere - these larger pieces seem to be better to find tight rings and heartwood than your average 2x4. After entirely botching the notching of a pair here is a liberated piece of it:
The tricky bit is that recall that the hull sides are not right angles, so we have to bevel the edges and bevel the stern and side in a consistent manner. (meaning this knee may not be level in space). This I did by putting a thin piece of ply in the corner here to represent the knee securely fit and then my assistant measured the angles needed for the bevel at four points on the knee.
From those points, I interpolate a line for the cut, cut out the bevel with a saw, and then get out the good watercolors.
This one’s not there yet. I put some paint pigment and a touch of moisture at the joint to see the fit. There is probably something more appropriate to use than Grumbacher watercolors, but it’s what I got. At this point, I iteratively plane, rasp, chisel, file, and gnaw away the painted areas until I get a snug fit. It takes a while.
Then in for a test fit: