Boat fuel gauges are notoriously inaccurate. Running your boat with the gauge tipping down toward E is asking for trouble.
Experienced captains still go by this old adage when considering range: Devote one-third tank to get to the destination, one-third to get home, and the last third as your margin of error.
That margin will see you through changes in weather or sea conditions, shifting currents or wind, or a forced change in course or a navigation error, all of which can impact fuel consumption.That margin will also cover your inaccurate fuel gauge.If you notice your fuel gauge is getting low and you question whether you’ll make it back to home port, start looking for an alternative, closer source of fuel, or a safe place to dock while you secure some fuel, even if that means hitching a ride to a gas station with some fuel jugs.
Newer boats may have a digital display or digital instruments () that measure how much fuel the engine(s) are actually using. If you know your tank holds 80 gallons, for example, you can set the fuel-use meter to zero when you head out with a full tank and monitor how much fuel you’ve actually used.
This data is much more accurate than the fuel gauge.