Lift and drag coefficient units/scale?

[Vince-vd]

Hi,

I wanted to input my own sail, rudder and keel models into your simulator model, but am wondering if you use a different scale or different units for the libfoil plugin. On your example boat, the cla for the keel is 10 and cda is 8. To the best of my knowledge even very high lift airfoils only have a coefficient of lift around 3. Would it be possible to elaborate on how you define these values?

Thank you,