high altitude prop

[Supragang]

This is the first year with this boat so I have some but not a lot of data points. I tend to be at Or near sea level, Delta or Berryessa (before it burned) Or 6000. I find I need a aggressive prop for the high altitudes and prefer the lower rpm’s at lower elevation. With 1k of lead and 8 adults I needed the low end at Berryessa. I’ll give up top end speed for easy surfing and not burning more fuel.

How much top end speed do you loose?