: Do you have a limit on a size for storage or transit? Is there a weight
: concern?
: I ask because I am wondering why are you thinking of shortening an existing
: design. I know there must be some reason, and perhaps if we knew that we
: could be more specific in answering your question.

: PGJ paul all the above, size ,storage, my building space is 20ft by 8ft so that is why.

By positioning the strongback diagonally in that space you would have plenty of room to build a 20 foot boat, and probably a 22 foot boat, and you would still have wide aisles so you would be able to easily walk around the boat. If this space is also your storage area, then the same applies.

Nick Schade has plans for a Great Auk double already. You might want to consider that rather than adapting something yourself. The plans are US$85, whih is the same as he is asking for the plans for the guillemot double, and that is just US$10 more than for the single place Great Auk. That is a small price to pay to spare yourself messing with the math and drawing.

It would be fairly easy to shrink either of these designs by a foot or two. YOu would out out the forms as directed, and then space them just a bit close together when you mount them on the strong back.

For example: Suppose you had a 20 foot long boat which had a frame for the bow, and another for the stern and then had 18 other forms spaced a foot apart along the length of the strongback. If you were to change the spacing of the forms from a foot apart (12 inches) to 11 inches apart then you would have a boat which was 17 inches shorter. If you made the spacing 11.25 inches apat then that 20 foot boat would be closer to 19 feet long.

In this case the math is fairly simple to do. Then, when you start applying your first two or three strips you can see if any forms need to be repositioned (maybe give or take 1/2 inch fore or aft) to get the lines of the boat to be smooth and streamlined. Do those minor adjustments and the rest of the stripping should go smoothly.

As for storage, it would not be difficult to cut one of these boats roughly in half, or into thirds. You would probably want a bulkhead behind the front paddler. Putting in two slightly separated bulkheads there, and then slicing between them, would seem simple.

For assemblyu or disassembly you would simply shift the front paddler's seat and back support to gain easy access to the nuts that hold the boat together. As a ballpark guess I'd say you would probably have one piece about 9 feet long and the other would be about 11. Those should be small enough to store.

Hope this helps

Good luck with your project.

PGJ