Modeling the hull as a mesh

The Subdivision Surface was great for shaping the hull. But now, to create the cabin and the cockpit, you have to change gears. You need some sharper corners and straight edges to define the cockpit and the cabin. For that, you'll shift back to using the extrusion. First you need to convert the surface to a mesh object, then you can create the cockpit, and use the cockpit to build the cabin.