Hi Goggo
The chine idea has been around for a long time in boating circles and it is called the double chine because there are two creases (chines) required to form the flat panel.
Thats how it appears in the surf board shape anyway.
Over 2 years ago I built a double chine downwinder (SUP)
A shaper mate of mine, Leigh Steven, has been doing chine short
b
oards for longer than that and they perform well. He did an 18' SUP downwinder way back and also helped me with my current 9' SUP wave board which was eventually shaped by our local man Nick Stranger.
I've been surfing it for 2 years and can't tear myself away from it.