constructing a ship hull with FC is very time consuming.
You can reconstruct the hull from the imported hull drawings
by using 3d splines, surfaces and sketches and some more.
Using the part and partdesign workbench alone is not enough.
And you should use the latest FC.018 snapshot for the work.
There was a long discussion in the german forum about constructing hulls.
The ship-workbench is not an option, because it dont work at the moment.
Do you know freeShip? It is for constructing hulls and doing the hydrostatics.