Furuno NAVNET 1724C User Manual
Page 134
4. VIDEO SOUNDER OPERATION
4-5
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.
20.0
NORMAL DISPLAY
BOTTOM
DISCRIMINATION
DISPLAY
HF
0
80
2
4
50
0
100
--
--
--
-
-
-
-
-
-
-
-
-
-
-
-
50
-
Zoom marker
Long tail = Hard bottom
Short tail = Soft bottom
Bottom tail
Bottom discrimination display
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.
SINGLE FREQ DISPLAY A-SCOPE
DISPLAY
HF
50
0
100
--
--
--
--
84
Strong echo (bottom)
A-scope display
Weak echo (fish)
No response
--
A-scope display