Operation Manual

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Using the autopilot | NSS Operator Manual
The set course to steer (CTS) and set wind angle are entered from the compass heading and
the wind transducer at the moment the WIND mode is selected. From that point the autopilot
will change the course to maintain the wind angle as the wind direction may change.
Tacking
 Note: The tack function is only available when the system is set up for SAIL boat type.
Tacking should only be performed into the wind and must be tried out in calm sea
conditions with light wind to fi nd out how it works on your boat. Due to a wide range of boat
characteristics (from cruising to racing boats) the performance of the tack function may vary
from boat to boat.
You can initiate the tack function both from AUTO and from WIND mode.
In both modes you can interrupt the tack operation, as long as the tack dialog is open,
by selecting the opposite tacking direction. When interrupted the boat will return to the
previous set heading.
Tacking in Auto mode
Tacking in AUTO mode is diff erent from
tacking in WIND mode. In AUTO mode the
tack angle is fi xed and as defi ned by the
user.
When tacking direction is selected the
autopilot changes the current set course
according to the set fi xed tacking angle.
Tacking in Wind mode
Tacking in WIND mode as compared to
AUTO mode can be performed when sailing with apparent or true wind as the reference. The
true wind angle should be less than 90 degrees.
The rate of turn during the tack will be given by the Tack time defi ned in the sailing parameter
setup (refer illustration above). The tack time is also controlled by the speed of the boat to
prevent loss of speed during a tack.
When you initiate the tacking, the autopilot will immediately mirror the set wind angle to the
opposite side of the bow.
Gybing
Gybing is possible when the true wind angle is larger than 120°.
The time to make a gybe is determined by the speed of the boat to make it as quick as
possible within control.
Tack and gybe prevent
You should use the autopilot with care when beating and running.
If the sails are unbalanced when beating, yaw forces from the sails can drive the boat into the
wind. If the boat is driven beyond the set minimum wind angle, the thrust from the sails will
suddenly disappear and reduces the boat speed. The boat will then be more diffi cult to steer
as the rudder will become less eff ective.
The tack prevent function in WIND mode has been implemented to avoid such situations. It
will react immediately when the apparent wind angle becomes 5° less than the set minimum
wind angle, and more rudder will be commanded.
See “Sailing
parameters” on page 40 for
further information.