Raymarine L365 GPS Receiver User Manual


 
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Before we explain the other pages, there are some general things you
should know about the operation of the FishFinder.
Choosing a Frequency
We said that the FishFinder uses sound waves to see through the water
under the boat. The frequency is a measure of how fast the sound
waves change or vibrate. The FishFinder uses sound waves with two
different frequencies 50 kHz and 200 kHz. Raymarine uses these two
frequencies because each is better for a particular purpose:
50 kHz frequency
Scans a wide area
Penetrates water well, good for deep water
200 kHz frequency
Scans a narrower area, but produces a more detailed view
Good for seeing fish near the bottom or fish close together
Better for use in very shallow water
Dual frequency (both 50 kHz and 200 kHz at once)
Has the advantages of both frequencies
Good depth penetration
Good detail in display
Using the Dual 50 kHz setting, the display is produced using the
signal from the 50 kHz beam, with additional information from the 200
kHz beam.
Using the Dual 200 kHz setting, the display is produced using the
signal from the 200 kHz beam, with additional information from the 50
kHz beam.
If you are using one of the dual frequency settings, you can get some
useful information from the fish symbols. If the fish is spotted by the
narrow 200 kHz beam, the fish symbol will be black or filled-in. If a fish is
detected by the wide 50 kHz beam, the symbol will be hollow.
Operating Instructions