Simrad Robertson AP9 Mk3, Instruction Manual, Page: 35 / 202

Operation
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2-7
Examples of incorrect RUDDER settings:
Fig. 2-2
Rudder settings
A value which is too low gives relatively large and slow oscillations
(s-ing) around set course, and several rudder commands are given in
the same direction before the vessel is back on course.
A value which is too high will give quick and increasing oscillations
(s-ing) around set course.
The correct setting of RUDDER will be approximately in the middle
of the settings described in Fig. 2-2
Press RUDDER, thereafter INCREASE or DECREASE for required
amount of rudder.
Range: 0.1 - 3.3.
Recommended start value: 0.6 - 1.5.
WEATHER
The WEATHER setting determines the number of degrees the vessel
may fall off the set course before any response is given to the rudder.
In calm weather it should be set to OFF which means that
theoretically the autopilot allows no deviation from set course. The
WEATHER value should be increased with increasing sea state. This
will cause the sensitivity to be decreased such that the vessel has to
fall off course with the number of degrees selected by the Weather
setting before a rudder command is given. The amount of rudder is
calculated by the heading error exceeding the set limit, multiplied
with the p-factor. This will prevent big rudder amounts and reduce
rudder activity.
In conditions where active steering is required, (e.g. following sea
condition), the value should be reduced.
Press WEATHER, thereafter INCREASE or DECREASE for required
sensitivity.
Range: OFF - 8°. (OFF is max. sensitivity).
Recommended start value: OFF - 3°.
Too little rudder
Too much rudder
Course to steer
Course to steer