Uwe, thanks for the response. The fit amidships looks good. Using your copy of the photo, the lower thick planks are aligned with laser match marks on the stem so they start in the right position. The plank that has the blue arrows pointing at it has not been installed, I am just showing that the precut plank curvature doesn't match what's needed for the next plank. The red arrow is longer than the green one and I think that is my error in wrestling the thick planks. I am working on the forward set of athwartships curved beams and that will give me a clue as to whether I have an overall hullform issue. Initial dry fits look pretty good. I think/hope I will be able to work around the gap issues above. Thanks again for your input.