Furuno GP-7000F Operator's Manual page 96

10. VIDEO SOUNDER OPERATION
Bottom-lock display
The bottom-lock display provides a compressed normal picture on the right half of the
screen and a 15 or 30 feet (5 or 10 meter) wide layer in contact with the bottom is ex-
panded onto the left half of the screen. This mode is useful for discriminating bottom
fish from the bottom echo.
Note: The range of the bottom-lock display can be changed at BOTTOM LOCK
RANGE on RANGES menu.
Bottom-lock
display
Fish school
Bottom-zoom display
The bottom-zoom display expands bottom and bottom fish echoes by the chosen
zoom range and is useful for determining 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.
Note: The range of the bottom-zoom can be changed at ZOOM RANGE on RANGES
menu.
Bottom-zoom display
10-6
88.7
ft
Bottom-lock display plus normal sounder display
59.8
Bottom-zoom display plus normal sounder display
Fish
school
30
20
10
0
50k
Single frequency display
50
60
70
ft
Zoom marker
Bottom
When depth changes,
the marker follows it automatically.
0
0.0
Zoom marker
50
This part is
zoomed.
100
Single frequency
display
50
100
50k