Navman TRACKFISH 6500 Installation And Operation Manual page 33

A Single fish
B Large school of fish
C Small school of fish
D Bottom
Bottom types
Mud, weed and sandy bottoms tend to weaken
and scatter the sonar pulse, resulting in a weak
echo. Hard, rocky or coral bottoms reflect the
pulse, resulting in a strong echo.
Frequency and cone width
The sonar pulse
generated by the
TRACKFISH transducer
travels down through
the water, spreading
outwards in a cone
shape. The cone width
is dependent upon
the frequency of the
pulse; at 50 kHz it is
approximately 45°,
and at 200 kHz it is
approximately 11°.
The differences in the
cone width affect what
is displayed. See
section 8-3.
TRACKFISH 6500 Installation and Operation Manual
A
B
C
D
Water
Depth
25
50
100
150
200
300
400
600
800
1000
NAVMAN
A Kelp / Weed
B Soft bottoms such as mud, weed and sand
show as narrow bands
C Hard bottoms such as rock or coral show as
wide bands
Cone width
at 50 kHz
20
40
80
45° cone
130
170
250
330
500
660
830
A
B
C
Cone width
at 200 kHz
5
10
20
11°
cone
30
40
60
80
120
150
190
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