Hey guys.

So I'm doing the pirate ship tutorial. To make the bottom of the boat, I created a NURBS sphere. Elongated it by selecting groups of vertices. Deleted the top half. Now Im supposed to drag a group of vertices on the end upward to match the shape of the boat. Only problem is the top line, which was formerly the center line of the sphere, doesn't bend along with the rest of the shape, as I move the vertices upward. Does this have to do with hard/soft lines? If so, how do I fix it?