Using G-Chart Cartography - Garmin GPSMAP 235 Sounder Owner's Manual

Using G-Chart Cartography

Once a G-chart cartridge has been inserted, the map coverage outlines for the
cartridge will automatically appear on-screen. Keep in mind that the display will
not automatically scroll to the map area or zoom to a level where you can see the
coverage outlines. If you do not immediately see the outlines, scroll the cursor to
the broad geographic area covered by the chart and zoom out to another
map scale.
The large outlined box shown is the main chart, which serves as the boundary
area for the entire cartridge. The small outlined boxes inside the main box are sub-
charts, which provide more detailed coverage of the area indicated. To view the
detailed cartography of any subchart, scroll the cursor to the subchart outline and
H I
use the and keys to zoom to smaller range scales. If the map outlines still
do not appear, check the 'Map Outlines' setting on the map options page to make
sure they are set to appear (see page 43).
Whenever you zoom past the usable range of the current electronic chart, the range
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field will display 'Ovr Zm' or 'No Map'. These warnings indicate that although you
may still have cartography, you should exercise extreme caution using the data. See
page 42 for more information on Overzoom and No Map modes.
When a G-chart cartridge is installed, the sounder will automatically use the
best available chart for display. As you enter and exit various subcharts, the system
will automatically display the appropriate chart for the area you are in. When you
leave the area covered by the main map of a cartridge, the sounder will default
back to using the built-in 64 nm database (32 nm in U.S.) if it is available at the
current scale.
If you are not seeing certain map items (navaids, depth contours, etc. on
offshore cartridges; highways, boat ramps, etc. on inland cartridges), check the
map configuration settings available from the map options page.
G-CHARTS
Using G-Charts
A B
A. Map outlines for G-chart offshore cartography.
B. Map outlines for G-chart inland cartography.
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