JAXAshby wrote in message
...

I see the rudder (prop in
reverse, boat static) altering the direction of the water
approaching the prop.

no, the water pressure of either side of th rudder is the same.

Now, perhaps it doesn't

it doesn't.

the water pressure on either side of a rudder is the same for
water drawn over
the rudder.

Those are statements, not explanations. That's why I'm stuck. How
about an explanation of those phenomena for a numerate old
thickie? Try third year fluid dynamics instead of first year. It
won't kill me.

JimB