TRACKFISH 6500
Installation and Operation Manual
59
NAVMAN
Warning: When you change to a
chart with a different datum, change the
TRACKFISH map datum again.
NMEA datum offset
If you select a map datum other than WGS
84, the map datum offset can be applied to
latitude and longitude coordinates sent on the
TRACKFISH NMEA output:
Latitude and longitude coordinates
displayed on any NMEA repeater do not
match the coordinates on the TRACKFISH.
Latitude and longitude coordinates
broadcast on any NMEA VHF transmitter
will be the same as the coordinates on a
WGS 84 chart.
Latitude and longitude coordinates
displayed on any NMEA repeaters match
the coordinates on the TRACKFISH.
However, latitude and longitude
coordinates broadcast on any NMEA VHF
transmitter will be slightly offset from
coordinates on a WGS 84 chart.
Map shift
Warning: Map shift is for eliminating
minor offsets. It should not be used if the
correct datum is available. Use map shift
with caution: incorrect application will cause
incorrect boat positions.
Some charts have consistent position errors.
To correct this, apply a map shift. After a map
shift:
The positions of cartographic features
(such as land, rocks, buoys and depth
contours) move on the TRACKFISH chart
display to where they should be.
The positions of the boat, waypoints,
tracks, and lines of latitude and longitude
on the TRACKFISH chart display remain
unchanged.
Applying a map shift
1 Move the boat to a known point on the
chart, for example a marina berth.
2 In the Chart setup menu, select
Map shift
.
3 Move the cursor to the position on the
chart where the boat actually is.
4 Press
and select
Set
.
5 Press
to set the new map shift.
The boat will now be displayed at its
actual location.
Clearing the map shift
Clearing the map shift removes any map
shift from the cartographic features on the
TRACKFISH chart display.
1 In the Chart setup menu, select
Map shift
.
2 Press
and select
Clear
.
3 Press
.
General submenu
Plotter mode
Only scales available on the chart card can be displayed.
If you press
or
to select a chart scale which is not available, on
the chart card, the chart display will change to this scale but will only display
the boat position and track (if enabled). The rest of the display is white with
black crosshatch lines and no chart information is displayed. This is useful
to zoom to a small scale to track small boat movements or if there is no
detailed chart for an area.
Mixing levels
Mixes lower detail charts with higher detail charts on chart boundaries.
:Lower detail chart is not shown.
:Lower detail chart shown; this is slower to redraw.
