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Inputting the Amount of Fuel Added to the Boat with a Garmin® Marine Device
When using the GFS™ 10 to calculate the remaining fuel in a tank, based on the fuel-flow rate, input the amount of fuel added manually to the tank during each fill-up.
To specify the amount of fuel added, follow the instructions specific to the chartplotter series, see owner's manual.
Current GPSMAP® Series1
Press the Home > Vessel > Fuel > Options > Select one of the following options
Fill Up Tank - Set fuel level to the maximum capacity
Add Fuel to Boat - Specify the amount of fuel added
Set Total Fuel Onboard - Specify the amount of fuel currently available in the fuel tank or tanks
1steps on legacy devices vary on wording see owner's manual,