Furuno FCV-667, Operator'S Manual

Page: 13 / 38

2-3
ZOOM mode (high or low frequency)
Three types of zoom displays are available: bottom-lock expansion, bottom zoom and marker
zoom. The zoom mode to be used can be selected on the main menu with ZOOM MODE.
5
Fish
2 20.7
0
40
Bottom-
lock
display
Normal
display
Zoom marker (yellow)
This section
is zoomed
10
20
30
0
4
3
2
1
BOTTOM-LOCK
This display provides a compressed normal picture on the
top 2/3 of the screen and a 5 or 10 meter (10 or 20 feet)
wide layer in contact with the bottom is expanded onto the
bottom 1/3 of the screen. This mode is useful for bottom
discrimination. Note that the seabed should be steadily
and distinctly plotted in red or reddish-brown. Adjust the
gain if necessary.
Note 1: The bottom-lock range can be selected on the
system menu [3].
Note 2: The zoom marker can be turned on/off on the
system menu [1].
0
10
20
30
40
15
20
25
36.4
Normal
display
Zoom
marker
(yellow)
Bottom
Bottom-zoom display
BOTTOM ZOOM
This mode expands bottom and bottom fish echoes two to
five times to vertical size of the screen, and it 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.
The zone automatically moves so that the bottom echoes
locate on the lower half of the screen.
Note 1: The amount of expansion can be selected on the
system menu [3].
Note 2: The zoom marker can be turned on/off on the
system menu [1].
14.7
0
10
20
30
40
15
20
25
28.2
Zoomed fish
school
Normal
display
Variable range
marker (green)
This section
is zoomed
Zoom marker
(yellow)
Marker-zoom
display
Fish
school
MARKER ZOOM
This mode expands selected area of the normal picture to
full vertical size of the screen on the left-half window. You
may specify the portion to expand with the VRM (Variable
Range Marker), which you can shift with [
▲
] or [
▼
]. The
area between the VRM and the zoom range marker is
expanded. The length of the segment is equal to one
division of the depth scale.