> What follows cannot possibly be considered real "advice" due to
> the fact that I really have no basis in expertise here. But as far as a
> free flow of intuition here goes:

The logical extension of this line of reasoning is that judges need to first be crooks, and psychiatrists have to be nuts before either can do their jobs. Fortunately, it is not necessary to always have experience before offering advice.

Your idea for scribing a piece of cardboard has defintie merit, but it is not necessary to have the deck assembled, much less installed. to do this. A straightedge running from the center deck beam to the end is all you need. Simple options are: a straight 1x3 or an eight foot aluminum, steel, or iron bar. If it hits an intermediate deck beam you either: A) move the deck beam closer to the center of the boat, B) shave, saw, plane or sand it down or C) raise the center deck beam a bit with shims. Measure each deckbeam individually before installing all of them. The set a couple in place and see that things are fine. Add more deckbeams, one at a time, making sure things stay aligned, until you have them all in. If the straightedge is riding more than 1/16 inch or 1mm to 2 mm higher than the deck beam you have to shim it up. You can use a dividers, ruler, or a scrap of paper to determine how much to shim things. Make a tick mark on the beam under the straightedge and use a pencil to write on the beam the amount you need to add at that spot. Plane the strips you are using for your shim stock to be slightly more than this amount before you glue them on, and you will need to remove very little wood after the glue sets.

Paul Jacobson