extrude non-planar 3D drawing

Hello all.

I am trying to model a boat in Solidworks.  The data for the boat comes as an offset table, which is a set of 3D coordinates.  I placed all of the coordinates in a 3D drawing and connected them via splines to form the outline of the hull.  I can't get any of the sections to extrude -- it always says that the direction must be defined for the extrusion.  I get that, but does that mean that I have to define a perpendicular vector for each section?  The problem with that is that the sections aren't planar -- they're curved in different ways.  Are there any other approaches that could work?

Thanks.

            Bret

SolidworksDrawings And Detailing