I have just put together the 2D curves from the boatplan of Hurley 22 way back from the 60s, and I now want to make a surfaced hull out of them in Rhino, so I can start modify my boat to make it seaworthy for the roaring fourties.
I cannot surface the hull with the “loft” function, it goes bananas, and I think it is because the curves are not aligned on the same axis.
Here is a picture of what I think is a good solution:
I frequently use the Patch command to create boat hull surfaces from sets of lines. It does require some experimentation. I usually create an initial surface using just the edge curves, and then use that surface as the starting surface in Patch.
Now that the buttocks lines are visible in your image, I would create plans on which your desired sections would lie. Then you can intersect each station plane with the buttocks lines and you will get points. The use Interpret Curve to click on each line from sheer to keel and get half sections. Do so at each plane and as I mentioned earlier, rebuild each new half section that you just created to have the same number of control points. Then you can loft them and get a surface that you can point edit to get a better fit to the stem.
In marine design, sections can be in any plane, and stations will be on the yz plane the ones I showed in red. I think that is what you indicated that you were trying to create in your image. Buttocks are on the xz plane and I have shown them here in blue and it looks like they are what you have to work from. Lofting a hull in that direction in Rhino will be harder.
Did you create new curves based on points from the old curves? If so and you used InterpCrv or CurveThroughPt? then the new curves will pass through the selected points. But if you used Curve the new curves will not go through the selected points. The selected points will be used as control points which are generally off of the curves.
There is a radius between the hull sides and the transom. Is that intentional? I always create the transom as a separate surface.
OffsetSrf is the simple way to create an inner hull surface if the hull is constant thickness.
For the transom curves shown I’d use the Patch command to create a surface. Also create the hull surface up to the transom. Then extend the hull and transom surfaces if needed so that they intersect, and trim each with the other.