16 echo 200, echo 300c, echo 500c, and echo 550c Owner’s ManualUsing the echoShowing the Battery VoltageBefore you can show the battery voltage, you must open the Full Screenpage (page 4), the Split Zoom page (page 5), or the Split Frequency page(page 5).1. Select MENU > Setup > Sonar Numbers > Battery.2. Select Show.Showing the Water Speed OdometerBefore you can show the odometer, you must open the Full Screen page(page 4), the Split Zoom page (page 5), or the Split Frequency page (page 5).To reset the odometer to zero, see page (page 8).1. Select MENU > Setup > Sonar Numbers > Odometer.2. Select Auto.Setting the number SizeBefore you can set the number size, you must open the Full Screen page(page 4), the Split Zoom page (page 5), or the Split Frequency page (page 5).1. Select MENU > Setup > Sonar Numbers > Number Size.2. Select a number size.CalibrationSetting the Keel OffsetThe keel offset compensates for the surface reading for the depth of a keel,making it possible to measure depth from the bottom of the keel instead offrom the transducer location.1. Select an option, based on the location of the transducer:• If the transducer is installed at the water line ➊, measure the distancefrom the transducer location to the keel of the boat. Enter this value insteps 4 and 5 as a positive number.• If the transducer is installed at the bottom of the keel ➋, measurethe distance from the transducer to the water line. Enter this value insteps 4 and 5 as a negative number.➊➋2. From any page, select MENU > Setup > Calibration > Keel Offset.3. Use and to select positive (+) or negative (-), based on thelocation of the transducer.