Calibrating the Water SpeedIf you select Temp, Spd for the Transducer option on the Setup subtab, you must calibrate the water speed to ensure the Water Speedshown on your unit is accurate. The calibration should take place inwater 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. On the Setup sub tab, highlight the Calibrate Water Speedbutton, and press ENTER.2. Bring the boat to a cruising speed. Both the top ground anduncalibrated water speeds are shown at the bottom of thecalibration window. Note your top speed, then stop the boat,and press ENTER.NOTE: You must have a transducer with a built-in speed sensoror seperate compatible speed sensor.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 again.If the boat is not moving fast enough or the speed sensor is notoutputting a speed, “Boat Is Not Moving Fast Enough To Calibrate”appears 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 376C Owner’s Manual 109SETTING UP AND USING SONAR > SETTING UP SONAR190-00508-00_0C.indd 109 11/6/2006 9:47:43 AM
