Furuno COLOR VIDEO PLOTTER 1833C Operator's Manual page 151

Bottom discrimination display
The bottom discrimination mode displays the bottom echo to help you determine
bottom hardness. A bottom displayed with a short echo tail usually means it is a
soft, sandy bottom. A long echo tail means a hard bottom.
Bottom tail
Long tail = Hard bottom
Short tail = Soft bottom
A-scope display (display only)
The A-scope display, available in all modes, shows echoes at each transmission
with amplitudes and tone proportional to their intensities, on the right 1/10 of the
screen. It is useful for estimating fish species and bottom composition. To turn on
the A-scope display, press the DISPLAY MODE soft key, select display mode
desired, then press the A-SCPE soft key to show "ON" on its label. For modes
other than SINGLE FREQ the screen must be split horizontally to show the
A-scope display.
84
200k
SINGLE FREQ DISPLAY
-
-
4
-
-
-
2
-
-
-
0
-
-
-
-
50
-
80
BOTTOM
DISCRIMINATION
DISPLAY
Bottom discrimination display
0
-
-
-
-
50
-
-
-
-
100
-
-
A-SCOPE
DISPLAY
A-scope display
4. VIDEO SOUNDER OPERATION
0
-
-
20.0
-
-
Zoom marker
50
100
-
-
200k
NORMAL DISPLAY
A-scope display
No response
Weak echo (fish)
Strong echo (bottom)
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