Garmin GPSMAP 175 - Manual (Page 35)

The map display has 16 available range scales from 1/8th to 4096 n.m. (1/4
to 7500km). The map scale is controlled by the
Z
key, with the current scale
displayed at the bottom of the data window.
To select a map scale:
1. Press up on the
Z
key to zoom out and down on the
Z
key to
zoom in.
The GPSMAP 175’s system has a built-in worldwide database to 64
n.m.(see Appendix F for a built-in coverage map), with more detailed
coverage available through the use of G-chart data cartridges (see Section 10
for installing and using G-chart cartridges). The GPSMAP 175 will display
cartography as long as there is chart information available for the range you’ve
selected. Map coverage will conform to the following conditions:
• When the selected zoom range is covered by either the internal database or
a G-chart data cartridge, cartography will be displayed.
• When the selected zoom range is covered by both the internal database and
a G-chart cartridge, cartography will be displayed using the data with the
best resolution.
• When the selected zoom range exceeds the resolution of the chart in use by
up to two settings, overzoom cartography will be displayed. The display will
not show any filled landmass areas, and an ‘Ovr Zm’ warning will appear
in the scale field. The lat/lon grid will also be turned on regardless of the map
configuration setting.
• When the selected zoom range exceeds the resolution of the chart in use by
more than two settings, all cartography will be replaced by a track plot
display, and a ‘No Map’ warning will appear in the scale field. The lat/lon
grid will be displayed regardless of the map configuration setting. Additional
caution should be used while navigating in track plot mode.
MAP PAGE
Selecting Map Scales
A. Whenever the
selected map scale
exceeds the
resolution of the
chart by up to two
settings, an ‘Ovr
Zm’ warning will
appear in the scale
field.
B. Whenever the
selected map scale exceeds the resolution of the chart by more than two settings,
a ‘No Map’ warning will appear in the scale field.
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175 Manual 7/31/98 3:56 PM Page 31