Hi Craig I can't say about surf I have only had mine in flat water. It will catch wakes from boats and barges nicely. I have a smart track rudder system that was installed after the picture was taken. The length can lift a rudder out of the water when you are in waves. The plans include a skeg which would work better in waves.
The stability is better than I thought it would be with a 19.5" beam. At the waterline you will run around 17.5. I think the stability may be due to the flatness of a hard chine bottom. Rounded hulls are faster but a S&G is so easy to build.
Again light weight will make a significant difference in performance.
I think this boat in a skin on frame build would be sweet. It would be easy to soften the chines. You could adjust length, beam, rocker, chines and so much more. Check out Cape Falcon Kayak. Brian has just built a skin boat for racing. It looks like a surf ski. Maybe similar to the Pax. Strip building will work also. Check out the Guillemot Mystery.
Loads of ideas out there.
Clayton Plunkett.