well the half out the water = more speed is not exactly correct !!!!!!!!!

The larger pitch is requiered simply becase the propeller is not fully in the water.
if 30% of the prop is not in the water then its not being used to propel the boat in forward motion,so obviously it would require more pitch on the remaining blades to keep the speed up.

i did have another look at the video and yes i was wrong the bullet is out the water sorry about that.
at one point the cone is not in use at all !!!!!


phill