Bottom-Lock Display (50 Khz Or 200 Khz); Bottom Discrimination Display (50 Khz Or 200 Khz) - Furuno GP-3500F-D Operator's Manual

11.2.5

Bottom-lock display (50 kHz or 200 kHz)

The bottom-lock display provides a compressed normal picture on the right half
of the screen and a 3 or 6 meters (10 or 20 feet) wide layer in contact with the
bottom is expanded onto the left half of the screen. This mode is useful for
discriminating bottom fish from the bottom echo. You may select the bottom lock
range. Refer to paragraph 11.19.
11.2.6

Bottom discrimination display (50 kHz or 200 kHz)

The bottom discrimination display shows the normal display as the right half, the
left half of the display is split in half horizontally with the bottom zoom display on
the upper half and the bottom discrimination display on the lower half.
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 trail
Long=Hard bottom
Short=Soft bottom
5.6 °C
BOTTOM-LOCK
DISPLAY
Fish school
38.6
Bottom-lock display plus normal sounder display
BOTTOM-ZOOM
DISPLAY
BOTTOM
DISCRIMINATION
DISPLAY
Bottom discrimination display
11. VIDEO SOUNDER OPERATION
10.0 kt
AUTO C
10
0.0
1'10"
8
6
4
Fish
school
2
0
m
50k
5.6 10.0 kt
°C AUTO C
1'10"
4
2
0
20
38.6
m
50k
40
0
Normal display
20
Zoom marker
40
60
80
0
0.0
Normal
display
20
40
60
80
11-5