Garmin GPSMAP 420 Owner's Manual

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Contents

Garmin GPSMAP 420 Owner's Manual Manual pdf 44 page image

3 GPSMAP ® 400 Series Owner’s ManualuSInG SonarScroll Speed—adjust the rate at which the sonar scrolls fromright to left (Ultrascroll, Fast, Medium, or Slow). If using aspeed-capable transducer, select Auto to have the scroll speedautomatically adjust to your boat’s water speed.Surface Noise—show or hide the sonar returns near the surface ofthe water. Hide surface noise to help reduce clutter.Whiteline—highlights the strongest signal from the bottom to helpidentify its hardness or softness.• Off—(default) Whiteline is disabled.• High—the most sensitive setting. Almost all strong returnsare highlighted in white.• Medium—many strong returns are highlighted in white.• Low—the least sensitive setting. Only the strongest returnsare highlighted in white.Overlay Numbers—show or hide battery voltage, watertemperature, water speed (if your transducer is capable), cruising,and navigation.NOTE: To show water temperature or water speed, change thesetting to Auto. If the connected transducer is capable, the datais shown.Advanced Sonar SettingsTo adjust advanced sonar settings, press MENU while viewing asonar screen.Range—the range of the depth scale on the right side of the screen(Auto or Manual Range).Gain—controls the sensitivity of the sonar receiver (Auto orManual Gain). To see more detail, increase the Gain. If the screenis cluttered, decrease the Gain.beam—when using a dual beam transducer, select a Wide orNarrow beam.Frequency—when using a dual frequency transducer, select howthe frequencies appear on screen (200kHz, 50kHz, Dual, or Auto).Zoom—zoom in to a section of the Full Screen. The zoom is off, orset to No Zoom by default. Four options are available:• 2x Zoom—twice the magnification.• 4x Zoom—four times the magnification.• bottom Lock—locks the zoom window to the bottom.• Split Zoom—opens the Split Zoom screen.Depth Line—quickly reference a specific depth (On or Off).A-Scope—(dual frequency only) a vertical flasher along the rightside of the screen (On or Off).