variable hulls

I like the concept of the variable hull rows, except now I have
more decisions to make when designing a ship (weak, strong,
now how many rows?  oh, what do I choose!).

But I have a question: What are the hull costs of ships with 
only one hull?	Or any other ship where the number of hulls is 
less then the number of rows chosen?  They now can pretend to 
have 6 rows and have their hull boxes cost 1 each?

Glen