Calibrating the Water SpeedIf you select Temp, Spd is for the Transducer option on the SonarSetup tab, you also need to calibrate the water speed to ensure thatthe Water Speed shown on your unit is accurate. The calibrationshould take place in water having little or no current.The unit automatically uses the GPS ground speed, if it is available,for comparison on the calibration. If a GPS ground speed is notavailable, use either your boat’s speedometer reading (not alwaysaccurate) or a stopwatch to determine your speed over a certaindistance. To find out your speed, divide the distance by the time.To calibrate the water speed:1. From the Sonar tab, Setup sub tab, use the ROCKER tohighlight Calibrate Water Speed, and press ENTER.2. Bring the boat to a cruising speed. Both the top ground anduncalibrated water speeds is shown at the bottom of thecalibration window. Note your top speed, then stop the boat,and press ENTER.Calibrating the Water Speed3. By default, the top ground speed is automatically shown. Ifa ground speed is not available, the top uncalibrated waterspeed is used instead. If the new speed is correct, highlightOK, and press ENTER.If you want to manually enter a calibration, press ENTERwhile the speed is highlighted, enter a new speed, and pressENTER.If the boat is not moving fast enough or the speed sensor is notoutputting a speed, “Boat Is Not Moving Fast Enough To Calibrate”shows at the bottom of the screen. Check that the speed sensorwheel is moving or safely increase boat speed. If there is a problemwith the speed sensor or if a speed senor is not installed, “WaterSpeed Sensor Is Not Working” appears at the bottom of the screen.Check connections of speed sensor cables.GPSMAP 396 Pilot’s Guide 141SETTING UP AND USING SONAR > SETTING UP THE SONAR PAGE
