Furuno NAVpilot-500 manual Weather, Track line and weather setting value, Rudder Gain

4. MENU OPERATION

WEATHER

When the sea is rough, the boat’s heading fluctuates to port and starboard. If the rudder is driven very often to maintain the set course, the helm mechanism may wear out. To prevent this, the weather adjustment makes the NAVpilot-500 insensitive to minute course deviations. You may choose a degree between 1° to 10°. Until the course deviation exceeds the selected setting, steering to correct the heading will not be initiated.

The illustration below shows boat’s track lines with weather setting 3° and 7°. When 7° is set, for example, the rudder is not driven until the course deviation exceeds 7°. Increasing the setting reduces activation of the steering gear, however the boat tends to zigzag. When the sea is calm, set a smaller value.

7

3

Weather = 3 Weather = 7

Track line and weather setting value

RUDDER GAIN

When the boat’s heading deviates from the set course, the NAVpilot-500 adjusts the rudder to correct it. The rudder angle (number of degrees) which is steered against every degree of course deviation is known as the rudder gain.

The following illustrations show how many degrees the NAVpilot-500 steers the rudder in order to nullify 10 degrees of course deviation with various settings of the rudder gain.

Rudder gain = 0.1	Rudder gain = 0.3	Rudder gain = 0.8
10	10	10

Rudder angle = 10 x 0.1=1 Rudder angle = 10 x 0.3= 3 Rudder angle = 10 x 0.8= 8

Rudder angle and rudder gain setting

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