: that. I am trying to find out what is wrong, if I find something I will
: let you know.

OK I think I know more now. First, the chines import method is non-trivial because when entering a bunch of chines there has to be a smart algorithm that decides how to connect the chines and where to put the corners. FreeShip's algorithm does not do it right for my purposes. I can see that this is generally a difficult problem so it is not good enough, let's forget about it.

The surfaces import method also did not work with my model at first but after reducing the rocker it suddenly gave results. It turned out to be a numerical problem, not a bug. The key was that the prismatic coefficient was out of range as a result of the amount of rocker that I specified in first instance. After reducing the rocker everything was (barely) OK.

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.

2) The visual representation of the waterline (I have the computations in my own software but not the plot) showed me that there was too much rocker and too much stuff protruding above the waterline.

3) FreeShip's graphics need improvement. My own graphics are much more primitive but they are better because they are based on cross sections with planes parallel to one of the axes, whereas FreeShip throws in a whole bunch of control net derived interpolation curves that are parallel to nothing. Therefore they are much harder to visualize. Besides that, it swamps the user with bunches of stuff that we don't need for our simple kayaks, and the color interpolation schemes are also miserable.

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.

5) I appreciate FreeShip because of the things that I learned and it accomplishes a broad number of things albeit not perfect.

So back to the drawing board if I decide that I prefer speed over surf/wave performance, and a sleek Greenlandish look.

Henk