GPSMAP 192C Owner’s Manual
71
M
AIN
M
ENU
>
U
NITS
T
AB
•
Heading
—selects the reference used in calculating heading
information. You can select from Auto Mag Var, True, Grid,
and User Mag Var. Auto Mag Var provides magnetic north
heading references that are automatically determined from
your current location. True provides headings based on a
true north reference. Grid provides headings based on a grid
north reference (and is used in conjunction with the grid
position formats described on page
70
). User Mag Var allows
you to specify the magnetic variation at your current location
and provides magnetic north heading references based upon
the variation you enter.
To enter a user defined magnetic variation:
1. With the
Heading
field set to
User Mag Var
, highlight the
heading reference field (immediately to the right), and press
ENTER
.
2. Use the
ROCKER
to enter the magnetic variation at your
current location, and press
ENTER
.
WARNING:
If
User Mag Var
is selected, you must periodically
update the magnetic variation as your location changes. Using
this setting, the unit does not automatically calculate and
update the magnetic variation at your present location. Failure
to update this setting can result in substantial differences
between the information displayed on your unit and external
references, such as a magnetic compass.
Manually enter a
magnetic variation.
•
Distance, Speed and Elevation
—select the units of measure
for distance, speed, and elevation readouts in Nautical
(nm, kt, m), Statute (mi, mh, ft), or Metric (km, kh, m) terms.
•
Depth
—select units of measurement for depth in Feet (ft),
Fathoms (fa) or Meters (m).
•
Temperature
—select the units of measure for temperature
in Fahrenheit (°F) or Celsius (°C).
