had a look to the modified files, thanks for help and time first.
This is much easier already, very interesting.
But... :-) I the frames shall not be inbetween the both surfaces, they should be on top of the offset surface, as the the hull surface and the offset surface will build a volume together with the other surface on the hull layer.
As offset was impossible with joined surfaces, because they do not stop at Y=0 when offsetted,
I decided to offset each single surface, cut it and join them afterwards.
Also ther eare more parameters needed to define the number of frames (Anzahl Spantabstände) and the distance inbetween (Spantabstand). This was already working in my version so far.
The frame distance is a result of the waterline length divided by numbers of frames.
In my version I had just defined a length for the aft and forward position of the frames.
The frames shall extend to the hole boat, not only in waterline length.
And for last the upper and lower edge shall be aligned with the hull offset surface.
Sorry if all this was somehow missunderstable.
I hope now my target comes out better.
Think I have to check out, what exactly the components do, which you have used.