Garmin GPSMAP 198C Owner's Manual page 88

U S > S P
SING ONAR ONAR AGE
Whiteline—controls how the unit shows information
about the bottom type (hard or soft). With the
Whiteline Off, the bottom return shows as red and
contains no information on bottom hardness. With
Whiteline set at Normal or 1-100%, the bottom return
becomes white with a red line indicating where the
water meets the bottom. To turn the Whiteline Off,
press the ROCKER down until the setting bar is all
Whiteline
the way at the bottom of the range and reads Off. See
Adjustment
page 91 for more detail on this feature.
Frequency—allows you to choose a transducer
frequency. Frequency refers to the pitch of the sound
that the transducer sends and receives. You can
choose 200kHz, 50kHz, or Dual frequency.
Depth Line—adds a horizontal depth
line across the screen that is used to measure the
depth of underwater objects. The depth of the
line appears in a box on the right side of the line.
Press up or down on the ROCKER to control the
position of the line on the graph. The depth shows
in a window on the right side of the line. To turn the
Depth Line Off, press the ROCKER up until the
Depth Line
setting bar is all the way at the top of the range and
Adjustment
reads Off.
82
Noise Reject
Adjustment
Scroll—adjusts the rate that the graph scrolls from
right to left. If you are sitting still or the graph is
moving too fast, slowing the scroll rate or pausing it
can be beneficial.
Frequency
Adjustment
Noise Reject—helps filter unwanted noise from
the graph. The Noise Reject tool can be turned
Off, set to Normal (automatically adjusts for
optimum viewing), or to a fixed 1-100% setting.
When setting the Noise Reject tool: the HIGHER
the noise rejection setting, the less likely the unit
is to NOT show fish or structure. To turn the
Noise Reject Off, press the ROCKER down until
the setting bar is all the way at the bottom of the
range and reads Off.
GPSMAP 198C Sounder Owner's Manual
Scroll
Adjustment