Fish Id - Humminbird 900 Series Installation And Operation Manual

to interpret sonar returns, and will display a Fish Symbol when very selective
requirements are met. When a fish is detected, a fish icon and its depth are
displayed above the return that has been classified as being a fish. Three
different fish size icons represent the intensity of the sonar return, and
provide an indicator of relative fish size.
DualBeam PLUS™ sonar models represent targets detected in the 200 kHz
narrow beam as orange fish symbols, and represent targets detected in the
83 kHz wide beam as blue fish symbols.
200 kHz, narrow beam
orange fish symbols
When Fish ID+™ is turned off, the 900 Series™ shows only the raw sonar
returns on the display. These returns will often result in "arches" forming on
the display, indicating potential targets. Due to the transducer beam angle,
the distance to a fish decreases as the fish moves into the beam, and then
increases as it moves out again, creating a Fish Arch when this distance
change is shown on the display. Boat speed, chart speed, and the position
of the fish within the sonar beam greatly affect the shape of the arch.
Fish ID+™
Fish ID+™ uses advanced signal processing
83 kHz, wide beam blue fish symbols
Transducer Cone and Fish Arches
To turn Fish ID+™ on or off:
1. Highlight Fish ID+ on the Sonar main menu.
2. Use the LEFT or RIGHT 4-WAY Cursor Control keys to turn the Fish
ID+™ setting On or Off. (Off, On, Default = Off)
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