WaveWitch: Drag Coefficients?

The "Long Boats and Drag" thread has me going on something that's
been bugging me for a few years now: would making my 12' 6"
WaveWitch (planing hull in the back, clipper front) 2-3" narrower
do anything significant for it's top end?

Right now, I'd say it's good for about 5.6 mph. I can do 5.2 mph
quarter miles... but can't do anything over 4.8 back-to-back.

I've been thinking about going back to a surf ski to get that
additional reward in the form of acceleration... but this thing
is just so convenient that I have to wonder about getting another
one, but narrower.

I've downloaded KayakFoundry... but wondered if anybody who
really knows about hull shapes/speeds could comment.
--
PeteCresswell

Per (PeteCresswell):
>I've downloaded KayakFoundry

I think I'm answering my on question about 2" reduction in
width's effect on hull speed: not much.

KayakFoundry's drag figures seem to agree with my subjective
experiences: the thing starts going asymptotic somewhere between
5 and 6 mph. A few inches less width does a little, but it's
not like somebody's going to cruise at 4.5 mph before and 6 mph
after.... more like 4.5 and 5...

Does this match the intuition of anybody with design experience?
--
PeteCresswell