wrote in message
oups.com...
Can anybody in the NG factually and authoritatively address the
relative physics and mechanical efficiency of paddlewheel vs. propeller
as propulsion sources for larger, displacement speed watercraft?


It shouldn't be too hard, a little trig, a little physics. The main
detractor from paddlewheel seems to me to be that the force has an upward
and downward component that represents wasted energy. So the thrust
varies as the sine of the angle of the blade to the water. To get the
overall efficiency, integrate sine x from the point where the blade
enters the water to where it exits the water.

That what you are looking for?