Eagle Electronics SeaCharter 502cDF - Manual (Page 150)

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To set Lat/Long Grid: From the Map Page, press MENU |
↓ to
M
AP
D
ATA
| ENT . Press
↓ to
L
AT
/L
ON
G
RID
L
INES
. With the option highlighted,
press ENT to turn it on (check) and turn it off (uncheck). After the op-
tion is set, press EXIT | EXIT to return to the main page display.
Map Datum Selection
Maps and charts are based on a survey of the area that's covered by the
map or chart. These surveys are called Datums. Maps that are created
using different datums will show the same latitude/longitude in slightly
different locations.
All datums are named. The GPS system is based on the WGS-84 da-
tum, which covers the entire world. Other datums may also cover the
entire world, or just a small portion of it. By default, your position
shows using the WGS-84 datum. However, it can show your position
using one of 191 different datums. Different datums can be selected; to
change the datum:
1. Press MENU | MENU |
↓ to
GPS S
ETUP
| ENT |
↓ to
D
ATUM
S
ELECTION
| ENT .
2. Use
↓ ↑ to select the desired datum and press
ENT .
3. To return to the last main page display, press EXIT | EXIT .
A list of the datums used by this unit is in the back of this manual.
GPS Setup Menu (left). Map Datum Menu (right).
Map Detail Category Selection
This menu determines which of the mapping features are shown on the
screen. This includes, waypoints, trails, icons, cities, highways, etc. You
can selectively turn on or off any of these items, customizing the map to
your needs.