"Roger Long" wrote in message
...
I'll try.

The answer will be found in conservation of energy. The energy books have
to balance in every system. The amount if drag of the water flowing over
the prop will exactly equal the energy being produced. With the prop
stopped, it is simply pull aft on the shaft. The prop isn't very
efficient that way. Try propelling a boat by putting the prop out ahead
on a long line and then pulling it in quickly. When the prop is
freewheeling, it is producing energy that is absorbed by heating up the
bearings and lube oil in the transmission, (or in Larry's case by charging
batteries).

It's slightly counterintuitive but, whatever energy is produced has to
have an exact mirror image in drag on the boat. Since the prop is making
energy more efficiently while turning, there has to be more drag.

--

Roger Long



Your explanation is pure nonsense. When the prop is fixed the energy created
is dissipated as heat in the water. When it is free to rotate some is
dissipated in the grease and bearings and some as heat in the water.


--
Peter Aitken