HI, I'm developing often hulls and boats, and the lines plan are god for building and not for modelling, for a better result I use a few sections and a network surface, or a 2 rail sweep.

And other thing consider only an half boat when you make the model, is bit complex making the keel and hull both in one surfaces.






Here a simple Dinghy made with loft.. but in IGES, the Moi version has no more sections.