Furuno CSH-8L - Manual (Page 40)

3. ADVANCED SONAR OPERATION
3-4
3.3 The Fish Alarm
The fish alarm generates an audio alarm when a fish echo above a certain
strength enters the alarm zone.
1. Operate the trackball to place the trackball mark on the starting point of the
alarm zone.
2. Press the [ALARM ZONE] key.
3. Operate the trackball to place the trackball mark on the ending point of the
alarm zone.
4. Press the [ALARM ZONE] key.
The display paints a fan-shaped alarm zone. The audio alarm will be
released when an echo enters the alarm zone.
Starting Point
Ending Point
Alarm Area
Fish alarm zone
Note 1: There must be at least three degrees difference between the starting
and end points to get a fan-shaped alarm zone as shown in (a) and (b)
below. Otherwise, a 360° alarm zone is painted as in (c) and (d).
More than 3˚
(a) (b) (c) (d)
Within 3˚
Fish alarm zones
Note 2: You may set the echo strength level which will release the audio alarm
with ALARM LEVEL on the SONAR menu. The setting range is 0-14.
Note 3: To show or erase the alarm zone, press the [FISH ALARM] key.