Simrad Maris ECDIS900 Operator's Manual page 278

Optimization settings
User defined NO GO Areas are plotted on the chart using ECDIS Object editor function. For
more details on how to plot areas and activate them as alarm object, see
V
OLUNTARY SPEED REDUCTION
This extremely important function is used to control the stress of the engine and on the hull
in heavy weather conditions.
Depending on the wave's height and direction the Captain may want to reduce the speed or
engine power according to the curves pre-defined during installation of the VDS.
When the Voluntary Speed reduction is activated, VDS will limit STW according speed curves
depending from wave conditions. It means that planned speed as major input parameter of
optimization is modified according voluntary speed reduction curves
O
PTIMIZATION METHOD
When the legs are longer than the "Minimum leg length to optimize" value, the VDS
optimization algorithm creates for each leg intermediate points which are used to investigate
the route possibilities.
The number of points for each leg depends on the selected accuracy:
Low accuracy: 25 intermediate points are created.
•
Medium: 30 points
•
High: 35 points
•
The highest accuracy gives the better optimization but requires high processing capacity and
the calculation may take some time depending on the power of the PC.
It is recommended to use Low or Medium accuracy for trans ocean routes and high accuracy
278
for narrow water.
User defined alarm.