Raymarine GPM400 Reference Manual page 47

If you have a Raymarine GPS attached, it will automatically update
when you adjust the datum. If you use a third-party GPS, you need
to update its datum separately.
CAUTION: Changing the chart datum does not cause any
waypoints or routes stored in the chartplotter to move on
the display, although their latitude and longitude changes
to reflect the new datum. When you add waypoints to the
waypoint list, make sure they are referenced to the same
datum.
Chart offset and cartography setup
This feature allows you to move the position of the chart to correct
positional errors in the cartography. The adjustment is indicated as
a distance north/west (+ve) or south/east (-ve) from your vessel to
a maximum of 1000m. An indicator in the chart window tells you
when chart offset is enabled.
Restore chart offset to zero when you begin using a chart with the
correct georeference.
Please report chart errors to Navionics (see
To change chart offset
1. Select Chart Offset in the Chart Setup Menu.
2. Toggle OFFSET to ON.
3. Press the SET OFFSET softkey.
4. Adjust the North/South and East/West offset values by pressing
the corresponding softkey and using either the trackpad or
rotary controller.
To restore chart offset to zero
1. Select Chart Offset in the Chart Setup Menu.
2. Press the SET OFFSET softkey.
3. Press CLEAR OFFSET.
To open the Cartography Setup Menu
1. Press the MENU button.
2. Highlight Cartography Setup.
3. Press the right-arrow on the trackpad.
FUNCTION
Chart Display
The level of detail shown on the chart.
Chart Grid
Grid lines of latitude and longitude.
Chart Text
Text appearing on the chart e.g. place names
etc.
Chart Boundaries
The line indicating the extent of the chart.
Spot Soundings
Number on the chart indicating depth.
Safety Contour
page 210).
Areas with depths shallower that the speci-
fied value are shaded in a darker blue than
those areas with depths greater than the
specified value.
Depth Contour
Set the interval for depth contours.
Hide Rocks
47
OPTIONS
Simple
Detailed
Extra detailed
ON
OFF
ON
OFF
ON
OFF
ON
OFF
OFF
7ft
10ft
16ft
20ft
33ft
66ft
(Contour always drawn at or
deeper than the selected
depth).
OFF
16ft
20ft
33ft
66ft
ALL
ON / OFF
Chapter 5: The Chart Application