The Cape Dory Board

Under sail a spinning prop does not spin as fast as the water passing it, when you are under power this is called"slip". When you are sailing and the prop is spinning but not moving through the water as fast as the hull it creates more drag than a locked prop because it creates more turbul...

My CD 33 seems to "hunt" while tied to a mooring in light wind. I know that the smaller Cape Dorys move alot but is a riding sail a must in a heavy wind for a 33?

I would like to know the actual hull speed for a CD33 while under power.