Setting the Keel OffsetYou can enter a keel offset to compensate the surface readingfor the depth of a keel, making it possible to measure depth fromthe bottom of the keel instead of from the transducer location.Enter a positive number to offset for a keel. You can enter anegative number to compensate for a large vessel that maydraw several feet of water.1 Complete an action, based on the location of the transducer:• If the transducer is installed at the water line À, measurethe distance from the transducer location to the keel of theboat. Enter this value in steps 3 and 4 as a positivenumber.• If the transducer is installed at the bottom of the keel Á,measure the distance from the transducer to the waterline. Enter this value in steps 3 and 4 as a negativenumber.2 Select Settings > My Vessel > Keel Offset.3 Select or based on the location of the transducer.4 Enter the distance measured in step 1.Setting the Water Temperature OffsetBefore you can set the water temperature offset, you must havea NMEA 0183 water-temperature sensor or a temperature-capable transducer to measure water temperature.The temperature offset compensates for the temperaturereading from a temperature sensor.1 Measure the water temperature using the temperature sensoror temperature-capable transducer that is connected to thechartplotter.2 Measure the water temperature using a different temperaturesensor or a thermometer that is known to be accurate.3 Subtract the water temperature measured in step 1 from thewater temperature measured in step 2.This is the temperature offset. Enter this value in step 5 as apositive number if the sensor connected to the chartplottermeasures the water temperature as being colder than itactually is. Enter this value in step 5 as a negative number ifthe sensor connected to the chartplotter measures the watertemperature as being warmer than it actually is.4 Select Settings > My Vessel > Temp. Offset.5 Enter the temperature offset calculated in step 3.Calibrating a Water Speed DeviceIf you have a speed-sensing transducer connected to thechartplotter, you can calibrate that speed-sensing device toimprove the accuracy of water-speed data displayed by thechartplotter.1 Select Settings > My Vessel > Calibrate Water Speed.2 Follow the on-screen instructions.If the boat is not moving fast enough or the speed sensor isnot registering a speed, a message appears.3 Select OK, and safely increase the boat speed.4 If the message appears again, stop the boat, and ensure thespeed-sensor wheel is not stuck.5 If the wheel turns freely, check the cable connections.6 If you continue to get the message, contact Garmin productsupport.Setting the Fuel Capacity of the Vessel1 Select Settings > My Vessel > Fuel Capacity.2 Enter the combined total capacity of the fuel tanks.Synchronizing the Fuel Data with the Actual VesselFuelYou can synchronize the fuel levels in the chartplotter with theactual fuel in the vessel when you add fuel to your vessel.1 Select Gauges > Engine > MENU.2 Select an option:• After you have filled up all the fuel tanks on the vessel,select Fill Up All Tanks. The fuel level is reset tomaximum capacity.• After you have added less than a full tank of fuel, selectAdd Fuel to Boat, and enter the amount added.• To specify the total fuel in the vessel tanks, select SetTotal Fuel Onboard, and enter the total amount of fuel inthe tanks.Customizing Engine Gauge and Fuel Gauge LimitsYou can configure the upper and lower limits and the range ofdesired standard operation of a gauge. When a value exceedsthe range of standard operation, the gauge becomes red.NOTE: Not all options are available for all gauges.1 Select a gauge.2 Select Gauge Limits > Custom > Edit Limits.3 Select an option:• To set the minimum value of the standard operatingrange, select Rated Min..• To set the maximum value of the standard operatingrange, select Rated Max..• To set the lower limit of the gauge lower than the ratedminimum, select Scale Min..• To set the upper limit of the gauge higher than the ratedmaximum, select Scale Max..4 Select the limit value.5 Repeat steps 4 and 5 to set additional gauge limits.Communications SettingsNOTE: Some settings and options require additional charts orhardware.Select Settings > Communications.Serial Port 1: Sets the input/output format for the serial port touse when connecting the chartplotter to external NMEAdevices, computers, or other Garmin devices.NMEA 0183 Setup: Sets the NMEA 0183 sentences thechartplotter transmits, how many digits to the right of thedecimal point are transmitted in a NMEA output, and howwaypoints are identified (NMEA 0183 Settings, page 31).NMEA 2000 Setup: Allows you to view and label the devices onthe NMEA 2000 network (NMEA 2000 Settings, page 31).Marine Network: Allows you to view the devices with which youare sharing maps, sonar, or radar. Not available on allchartplotter models.30 Device Configuration