Lets use 0.5 mtr height as a start of point. Later it can always be raised or lowered if that is needed.
You can also measure your own daggerboards and get a rough estimation of good starting point for height.
I as a Taipan sailor want more height above the water, my current design can flap the wave now and then when I doublehand. I seem to remember my hull is 0.45 mtr high at the daggerboard well.
Wouter
Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands