User's Manual

Table Of Contents
NACOS Platinum
ED 3100 G 140 / 04 (2011-11)
Operating Instructions
III-3 Permanent Area for Navigation
III Main Applications.fm / 10.11.11
III-38
Speed through Water - STW
1)
Next to the depiction STW there is a small indication like an
arrow-head. This is the speed vector indicator. It shows the
direction of the vector addition of the longitudinal and the
transversal own ship´s speed through water.
If the ship is moving straight forward through the water, the
arrow head points upward, if it is moving straight backward,
the arrow head will point downward.
The arrow head may also point into any other direction,
then the transversal speed component makes the ship move
sideways through the water
2)
.
AUTO
Means that the STW or waterspeed sensor is chosen by the system automatically.
The best available sensor will be used. If a failure occurs on the actual sensor,
the backup sensor is chosen if available, and a warning is given..
Log x
The selected speed log is used as system sensor for water speed. The sensor
selection mode is manual.
Manual
The actual STW of the own ship can be entered manually. In case
a manual value is presenlty used, the indication of the value is
preceeded by a in the same line.
Before having changed the speed sensor to manual mode, use the Set Speed... function in order to
enter the desired value, which should match as good as possible to the real speed through water of your
ship.
1)
The selected CTW/STW vector for speed through water is used as the data source for Water Stabilisation of
the targets in the radar PPI/chart area.
2)
Transversal speed information is only available if a 2-axis speed log is connected.
Speed vector indicator
Longitunal
Speed
Transversal
Speed
Vector addition
(resultuing Speed)