Add on and nurbs

Try the Curviloft plugins. Skins between a set of lines/curves. Takes a bit of getting used to with regards the order of curve selection, but once you do, it’s a nice plugin for those more organic shapes. Hope this helps.

if you wanna do true NURBS modeling go for a NURBS modeler, a cheap one here.

for modeling boat hulls check the fine DELFTship too.