Furuno NAVpilot-300 Operator's Manual page 53

Set rudder gain so that the boat does not make frequent yaw. The figure shown
below provides general guidelines for setting rudder gain.
Fast
Calm
Light
Low
7. Select [Counter Rud.]. The counter rudder setting popup appears.
8. Set the counter rudder as required. The setting range is 0 to 20 and the default
setting is 1.
If the boat is heavily loaded, the heading could change excessively because of in-
ertia. This phenomenon causes the boat to "overshoot" the intended course. If this
happens, the NAVpilot will steer the rudder to the opposite side and the heading
will turn in opposite direction excessively again. In an extreme case the heading
oscillates several times until it finally settles in the new course. An adjustment
known as "counter rudder" prevents this kind of oscillation.
Counter rudder is usually not required for small boats. When your boat zigzags a
lot before settling in the new course, increase the counter rudder setting.
Counter rudder:
small setting
Counter rudder:
proper setting
Slow
Light
Low
9. Select [Manual Trim]. The manual trim setting popup appears.
4. HOW TO CUSTOMIZE YOUR NAVPILOT
Speed
Sea State
Load Condition
RUDDER GAIN
Manual Parameters
Weather:
Rudder Gain:
Counter Rud.:
Prev
Large course error
The counter rudder feature functions to smoothly
return ship's heading toward intended course.
Speed
Load Condition
COUNTER RUDDER
Manual Parameters
Manual Trim:
0. 0°
Prev
Slow
Rough
Heavy
High
1°
3
1
Ent
Fast
Heavy
High
1°
Ent
Intended
course
4-3