Scooby... What measurment parameter differs on the F18's that effect the SCHR rating but still allows heads up competition within the F18 class. If the capricorn is racing the tiger and infusion heads up... What measurement could you make that would discrimate between the boats?

This simply makes no sense.... Ditto for the A class....
Yes... they are changing their hull shape... but NO measurement system (that we can afford) will take into account these differences.

In fact.. if your measurement system DID discriminate between the F18's... you would have a real problem.

Ergo... a yardstick system with enough data COULD discriminate between fast and slow A cat designs... Then again As Wouter will point out... the differences are likely to fall into the noise... (that's why we round off the numbers and don't carry the floating point to nnn decimals)

Take Care
Mark