Using Sonar
58 GPSMAP 400/500 Series Owner’s Manual
3. Press .
From the paused screen, press > to continue
scrolling.
—adjust the range of the depth scale on the right side of the screen
(, or to adjust manually, ).
—controls the sensitivity of the sonar receiver (, or to adjust
manually, ). To see more detail, increase the gain. If the screen is
cluttered, decrease the gain.
—when using a dual frequency transducer, select how the
frequencies appear on-screen (, , ,or ).
—zoom in to a section of the full screen. The zoom is off, or set to
by default. Four options are available:
• —turns zooming off.
• —twice the magnication.
• —four times the magnication.
• —set the depth range of the magnied area manually. Select
and then use the > to set the depth range of the
magnied area. Select and then use the > to increase
or decrease the magnication of the magnied area.
• —locks the zoom window to the bottom.
• —displays the Split Zoom screen (page 55).
(available only when is set to )—reduces on-screen
visual clutter (usually from electrical sources) on the screen. Select the top
slider bar to manually adjust the value of noise rejection. Manually adjusting
the amount of noise that is rejected helps ne-tune the sonar to show the most
detail with the least noise.
When is set to (and is set to ), you can
individually adjust noise rejection for each frequency.
