okay, yo-yo. which WAY is the rudder deflected if it is pushed to port?

please explain your reasoning.

the water pressure on either side of a rudder is the same for water drawn
over
the rudder.
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Only if the rudder is parallel to the direction of flow. At an angle
to the flow, water is deflected, momentum is changed, force is
created. It's not very much force in reverse, not enough to be useful
for maneuvering, but a force nevertheless.