Design measurements

[sooty]

I have drawn my own plans for a 4.5 metre boat I will build in ply.
I have built a model and like it.
I drew up the plans on graph paper and this is the problem.
Where two lines intersect on the paper I can take an accurate measurement. In the middle of the graph square is no mans land and as the lines of the boat curve some are in the middle of nothing.
A small error in my plans will mean a big error in the width of the ribs.
My model is good but not accurate enough to take measuremnts off.
Would appreciate anyone's help.
This is my first attempt to build a boat.

[kiwi]

You are mesuring from a base line?

You only need key points. You mark them on your ply then join the points by tracing along a flexible batten.

Tony