Furuno GP-7000F - Manual (Page 93)

10. VIDEO SOUNDER OPERATION
10-7
Marker-zoom display
The marker-zoom display expands a selected area of the normal sounder picture
to full vertical size of the screen on the left-half window. You may specify the
portion to expand by operating the VRM (Variable Range Marker), which you can
shift with the [ENTER] knob. The area between the VRM and zoom marker is
expanded.
Note 1:
The VRM is set independently from other displays in case of multiple
displays.
Note 2:
The range of the bottom-lock can be changed at BOTTOM LOCK
RANGE on RANGES menu.
0
50
100
50
40
30
20
12.8
VRM
This area is zoomed.
Single frequency display
Fish school
Zoom marker
Zoomed fish school
Marker
zoom display
25.0
50k ft
Marker-zoom display plus normal sounder display
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.
Note:
The range of the bottom discrimination can be changed at BOTTOM
LOCK RANGE on RANGES menu.
Long tail: Hard bottom
Short tail: Soft bottom
Seabed tail
50k
79.5
Single
frequency
display
ft
Bottom discrimination
display 0
50
100 50
0
10
This area
is zoomed.
Bottom discrimination display