If I understand you correctly, you have in essence made the boat a 1/2" too long (or too short). This does not matter.

: I finally got the setup of my "Guillemot Expedition Single" perfect
: ... at least I thought I did.

: I opted to place the cleats on the back side of the forms, leaving the center
: line's more visable, and sight the whole boat from the bow. This meathod
: just seemed to work for me and all went well. I was well chuffed after the
: previous results I had had.

: However I now realize that I have made a mistake :o(
: I placed all the forms on the back side of the alignment mark ! This
: effectivly means that I have lengthened the kayak by 1/2" (12mm)
: between forms 10 and 11.

: Question is, is this enough of a problem that I should take off forms 11
: through 17 and reposition them ?

: If you guys say I should then I will, if you say that it won't make a big
: difference to the handling of the boat then I could do without the extra
: work and will get on with the stripping :o)

: Cheers
: Ian