Raymarine L470 instruction manual Operating Instructions, Bottom coverage

create wider lines. Unlike the scrolling FishFinder Page, the A-Scope does not show a history of scans; instead, it is a “real-time” display. The shape of the A-Scope display shows the result as the sonar beam spreads as it penetrates deeper into the water.

Bottom coverage

The digital number at the bottom of the A-Scope image indicates the bottom coverage. This is the diameter of the sonar beam where it meets the bottom. This is computed using the beam angle of the transducer for the frequency you have selected. If the entry for Depth Units in the System Setup Menu is set to Feet or Fathoms, the bottom coverage will be reported in feet. If the Depth Units entry is set to Meters, the bottom coverage will be reported in meters. The beam angle used for the computation depends on the frequency selected in the Setup Menu:

Frequency Bottom Coverage Beam Angle

200 kHz	16°
50 kHz	65°
200 DUAL	65°
50 DUAL	65°
SPLIT	16° (top);

65° (bottom)

If you want to exit from the A-Scope Mode, press the A-Scope button again. The unit will return to the FishFinder Page.

Operating Instructions 53