Furuno GP-3500F - Manual (Page 202)

11. VIDEO SOUNDER OPERATION
11-30
11.15.3 Fish alarm (B/L)
The bottom-lock fish alarm sounds when a fish echo is within a predetermined
distance from the bottom. This alarm is available for the bottom-lock and bottom
discrimination displays. This alarm is useful to detect bottom fishes. Note that
the sensitivity of the fish alarm can be set on the ECHO SOUNDER SYSTEM
SETUP menu. For further details, see paragraph 11.18.
1. Press the [MENU] key to show the main menu.
2. Press the [6] key to show the ALARMS SETUP menu.
3. Rotate the [ENTER] knob to select FISH ALARM (B/L).
4. Press the [1] key to select “1. ON.”
5. Rotate the [ENTER] knob to select DEPTH of FISH ALARM (B/L).
6. Press the numeric keys to enter the stating point, and then press the
[ENTER] knob.
The starting point is range from bottom.
7. Rotate the [ENTER] knob to select RANGE of FISH ALARM (B/L).
8. Press the numeric keys to enter the alarm range from the ending point, and
then press the [ENTER] knob.
9. Press the [MENU] key to close the menu.
The white alarm marker appears at the left of the Bottom-lock and Bottom
discrimination displays.
Note: To turn this alarm off, select “2. OFF” at step 4.