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?