I use a cheap lazer pointer, and place in in a V-block. I know I know the lazer light will bend because of gravity, but even my boards are not that long.
I see mid-points as relative, if you surf front foot heavy or are shaping a fish with a foil foward setup your mid point might actually be off center if you follow. I use the wide/thick point as my reference for rocker and measure flip/entry/tail etc. using the foil of the board. no fancy measurement techniques though just a straight edge and a ruler, not super accurate but it feels good oh yeah!!!!!!!!
Where I can find the Pleskunas tools?
Well, but what if you don't want to take another board to copy that rocker, what if you want to shape it yourself, how do you do that, i've read a lot of topics but i couldn't find any.........