Using Sonar
Advanced Sonar Settings
To adjust advanced sonar settings, select Menu while viewing a sonar screen.
Gain—controls the sensitivity of the sonar receiver (Auto or, to adjust manually, Up or Down). To see more detail, increase the gain. If the screen is cluttered, decrease the gain.
Sonar Scroll—select to stop scrolling. Select Create Waypoint to save the location as a waypoint, and select Resume to continue scrolling in real time. For more information on waypoints, see page 23.
Frequency—selects how the frequencies appear on screen (200kHz, 50kHz, or Dual).
Zoom—zoom in to a section of the Full Screen. The zoom is off, or set to No Zoom, by default. Four options are available:
•2x Zoom—twice the magnification. Select Up, Down, or Auto to set the depth range of the magnified area.
•4x Zoom—four times the magnification. Select Up, Down, or Auto to set the depth range of the magnified area.
•Bottom Lock—locks the zoom window to the bottom. Select Up, Down, or Auto to set the depth range of the magnified area.
•No Zoom—turns zooming off.
Depth Line—quickly reference a specific depth (Show or Hide). When Show is selected, press up or down on the ROCKER (GPSMAP 4000 series) or touch and drag the line (GPSMAP 5000 series) to set the depth of the reference line.
Range—the range of the depth scale on the right side of the screen (Auto, or to adjust manually, Up or Down).
Sonar Setup—opens the Sonar Setup screen. See page 47.
Sonar
Using
