GPSMAP 292/298 Owner’s Manual 77
USING SONAR > SONAR TAB OPTIONS
Sonar Tab Options
Show Numbers Option
To access and change a setting on the Sonar tab:
1. Press and hold ADJ/MENU to access the Main Menu. Use
the ROCKER to highlight the Sonar tab.
2. Using the ROCKER, highlight the sub tab and then the field,
and press ENTER.
3. Highlight the setting, and press ENTER.
4. Press QUIT to return to the Sonar Page or a previous page.
General Sub Tab
Water Type—because sound waves travel through fresh and salt
water at different rates it is necessary to select the water type to
ensure accurate readings on the unit.
Keel Offset—used to offset the surface reading for the depth of
a keel. This makes it possible to measure depth from the bottom
of your keel instead of from the transducer’s location. Enter a
positive number to offset for a keel, or enter a negative number to
compensate for a large vessel that can draw several feet of water.
The Keel Offset reflects in the depth reading.
Keel Offset:
Transducer at
Surface Enter (+)
positive number to
show depth from
bottom of keel
Keel Offset: Transducer
at Bottom of Keel Enter
(-) negative number to
show depth from surface
