Originally Posted by Floyd
Not sure sail size and weight are linear.Infact pretty sure they aren`t.
Agree with you re Acid 86/K89 though.
Thanks for repy.
About linear. Wind force is exponential but locally a linear approximation is effective.
Try: 0.65 x Weight (Kg) / wind speed (meters/sec)
For example, at 8 meters/sec (15.5 knots) I am on a 5.5 square meters sail, at 12 m/sec (about 23 Kn) I am on a 3.7 that underestimate a bit the size but is not bad as an estimate.