As I have been looking for a new board, and studying the dimensions of the candidates very closely, I decided to check my current fleet to see how they stacked up against the stated measurements.
It seems none of them are accurate, with some very wide variations. It also seems that manufacturers measure boards along the rocker line rather than overall, something I find odd. I guess you have take quoted dimensions with a grain of salt. Anyway here's what I found:
Hahaha wait till you get into stated volumes, actual volumes, virtual volumes, stated and actual weights
There's good guide here
www.sailing.org/classesandequipment/equipmentcontrol/measurement_certifications.php
www.sailing.org/tools/documents/ISAFListSlalom-[8370].pdf
I reckon that's why the manufacturers use 'fluid' terminology such as flow, cross, carve, and magic to describe their product! 
