Furuno FCV-30 - Manual (Page 66)

2. WINDOW DISPLAYS
2-12
Setting bottom lock zoom range
1. Click Setting.
2. Click Echo image.
3. Click ▼ in the Zoom range box and push the left button.
Zoom range options
4. Click the setting you wish to use.
5. Click the OK button.
2.2.6 Bottom zoom window
The bottom zoom window expands bottom and bottom fish echoes by the zoom range
selected. 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.
00:00:28
34 42.616' N
135 19.740' E
60
TS
30
20
40
0
Fish school
41
43
45
47
49
51
Bottom zoom window