For years, on occasion, I've have been involved with teaching someone
boat handling, using single and/or twin screw inboards.
Naturally, (especially on twin screw+) the issue of rudder use arises (
from here we will consider this a twin screw+ discussion).
So that everyone knows, I am a STRONG proponent of rudder use, but I
understand many of the arguments against (G just don't agree with all
of them or feel the argument doesn't really address the issue).
In all of my discussions, I have had a problem with the term "steering",
as in "the boats moving too slow to steer with rudders", or "rudders are
not effective at these speeds".
At any rate, I knew I was never able to explain my point clearly and
concisely.
Recently, for some unknown reason, I remembered a TV show on jet
fighters which discussed (I believe) thrust vectoring, and it dawned on
me that this may be just the term to describe what I am trying to get
across to those I am teaching.
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?

otn