Simrad AP25 - Manual (Page 46)

Simrad AP25 Autopilot
44
20221495F
Tack and gybe operations
Gybing is possible when the true wind angle is larger than 120°.
When a gybe is initiated, the
wind angle will first be set to
170°T on the same side as the
current wind angle. The main
sail should now be hauled.
With the main sail safely
hauled, the wind side may be
changed. This is done by
pressing either PORT or
STBD buttons depending on
the way the boat should
continue to turn. The new set
wind angle will then become
the same as the wind angle set
before the gybe operation
started.
The rate of turn when
changing wind side in a gybe
will be the highest possible,
determined by the
performance of the drive unit.
Tack and gybe prevent
When beating and running, sailing is at the most critical.
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 minimum wind angle, the thrust from the sails will
suddenly disappear and the boat speed reduced. Then the boat
will be even more difficult to steer because the rudder will
become less effective.
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. Additional amount of rudder will be commanded to
immediately increase the wind angle.
When running, it is difficult to steer the boat with waves coming
sideways or from behind. The waves may yaw the boat so that