With this in mind, for those with twin screw boats, if I told you that
rudders were important tools of boat handling, but not to be considered
for steering, rather for "thrust vectoring", when maneuvering around a
dock, etc., when kicking an engine ahead, both positive and negative
...... would you understand what I was saying?


No, I would think that most people would be more confused.

To begin with, I would start by pointing out that there is a big difference
between how an inboard reacts and how I/Os or outboards react. There is
also a big difference between what I call "large rudder" and "small rudder"
boats.

A typical sail boat has a "large rudder" which becomes effective, in either
forward or reverse, as soon as the boat is making way.

A typical power boat has a "small rudder" which either needs a significant
amount of boat speed or to have the prop pushing water past it. These
rudders are generally ineffective in reverse.

The basic concept of twin engine inboards is that you consider the rudder to
only be a factor when the engine is in forward. Ignore it for the engine in
reverse.


Rod