THANKS everyone. Regarding my 9’6" semi-performance single fin: I’ll definitely be putting in a slight tail vee, but will withhold the double concave idea for now. I’ll make a very flat bottom with a slight concave running from aprox. 18" behind the nose thru the beginning of the single fin box. Sounds like a “rush” (of water) to me!
I’m a little late to check on this one, but Steve Walden has a single concave going into a double in the back on his Magic Model. Although he has sidebite removables, I surfed a 9’-0" as a single-fin in Hawaii. They have lots of tail rocker so they turn on a dime. A little slow in trim, but nose-rideable. They also have chined rails front to back. It all seems to work together pretty well.
I’m a little late to check on this one, but Steve Walden has a single concave going into a double in the back on his Magic Model. Although he has sidebite removables, I surfed a 9’-0" as a single-fin in Hawaii. They have lots of tail rocker so they turn on a dime. A little slow in trim, but nose-rideable. They also have chined rails front to back. It all seems to work together pretty well.