I have bought and read "The Strip Built Sea Kayak," and am curious about changing the length of the Great Auk. I would rather build a 10' kayak instead of a 17' which the book lays out. This is the first boat I will be building so I am not sure how to go about it. The only thing I found in the book was that an "18', 10' or tandem kayak could be built by simply adjusting the forms." Would this change the shape of the boat? Do I need to draw different forms?