: As much as I like to bitch and moan about FreeShip, I learned a few things:
: 1) The prismatic coefficient range problem made me check what it means and
: it showed (Nick's page) that fine "Greenlandish" hulls are lousy
: performers at higher speeds. Min was so low that I should really consider
: adding more volume to the bow and stern, if speed is my goal.

: 4) Traditional SOF kayaks are lousy performers speedwise not because of loose
: skin but because of their low prismatic coefficient (I'm not talking
: Baidarkas because they are different). They are probably better at low
: speeds and in the surf and waves, though.

Kaper uses those few components for calculations. I myself prefer Michlet because it actually uses the real hull for calculations. In real world kayaks Kaper should do pretty good, but if you make some strange shapes the results might not be so right.

Ok, and then about the "lousy" performers.

There's many kinds of Greenland kayaks. I have information from about 40 in my webpage. Some are "slow" some fast. The fastest do well against modern racing sprint kayaks under 12 km/h (or so) speeds. So you can not say them to be lousy performers. The underwater body of KOG #6 is stunning in performance view - it has low resistance in slow and high speed. (That is if Michlet does the calculation correctly).

I think slowish performance of some kayaks does not come from CP, but from waterline lenght mostly. And that comes from the fact that these kayaks were done for real world paddling in real waves. You won't be happy to paddle 6 metre hull without rocker in short waves.

It's actually quite easy to design fast sprint kayak for flat water. Michlet's Godzilla optimisation will shoot optimum hull for given speed quite easily. You might not want to paddle that in waves though.

So there's a need for kayak for some typical (or maybe worse) conditions and the kayak must work in those situtations. Sprint racing kayak will do fine in high speed and flat water. It sucks in slower speed and in small waves.

A Greenland hunting kayak must work well in waves in that area. After that comes speed or maybe resistance in different speed ranges. Also at 20th century the firearms created more demands for kayak, stability and such.

Baidarka's have usually quite long waterline - while typical greenland kayak has 1 metre shorter waterline than the kayak, baidarka typically has waterline quite close to hull lenght. I've had couple Baidarka models in Freeship/Michlet and considering the waterline lenght they aren't so different from Greenland kayaks in speed side.

I'm starting to build kog#77 just now. It's long kayak but has shortish waterline. Won't be a speedboat but should do fine in waves and also it's supposed to be great in resistance at 6-7 km/h. That's the speed where most kayakers paddle their kayaks. I think too many are looking for fast kayak and then they'll just paddle at middle speeds, like 8 km/h. Why to get a fast kayak if you don't have the power to run it?
I'm also thinking to build more challenging craft for myself later. For that kayak I'll look for speed and handling in waves. It's going to be a greenlander too. The greenland kayaks shine if you want good kayak in fast and slow speeds.

Here's couple images to see that Greenland kayaks do have some differencies - not all have fine and pinched ends:

http://personal.inet.fi/koti/tonivee/kog77.jpg
http://personal.inet.fi/koti/tonivee/kog103.jpg

Btw. Your kayak looks quite interesting. The chine form especially. I guess you are looking for high initial stability, ease of paddling and low secondary stability. Interesting look in any case.