Page
16
491 Echo Sounder Operations Manual
Using automatic mode
To operate the echo sounder automatically, just press
AUTO
.
All of the 491’s adjustments will be set to produce a useful
picture under most conditions. When you’re too busy to
optimize the settings manually, the echo sounder can
automatically set the optimal gain, clutter, and range settings,
to show an excellent picture, from the surface to the bottom.
When you select auto, the range setting may change from time to
time to keep the seabed in view as the water depth changes.
It is recommended that the 491 be operated automatically
whenever possible. The 491 can reliably detect the seabed
depth only when it controls the gain and clutter settings.
You can always press
AUTO
on the
ECHO
screen to remove
any manual settings you’ve made and return to the standard
automatic configuration.
Cruising or fishing
Automatic mode has two variations:
autocruising
and
autofishing
.
•
autocruising optimizes the gain and clutter for tracking
the bottom, with less emphasis on any fish in the water
•
autofishing optimizes the gain and clutter for searching
for fish
Press
AUTO
to switch between autocruising and autofishing.
The colored tab below the menu key indicates whether the
unit is optimized for cruising or fishing.
The status tabs
Colored status tabs just below the
AUTO
and
PICTURE
keys
are green when the echo sounder is operating fully
automatically. They turn yellow when any of the settings has
been set manually. (In some cases, the picture tab may be
yellow while the auto tab is still green, if the Noise Limiter is
turned on, for example.)
