5 Tips to Safely Refueling a Boat
Refueling a boat is no different than gassing up your car or truck, right?
Not quite.
Flammable fuels like gasoline and diesel can cause onboard risks that you wouldn’t experience on land.
For example, gasoline vapors are heavier than air and can accumulate in low-lying areas like the bilge, creating an explosive hazard that could be ignited by a single spark. Seemingly small oversights—leaving an open flame unattended or skipping ventilation—could lead to big problems.
Beyond safety, improper fueling can result in environmental damage, with legal consequences under laws like the Oil Pollution Act of 1990 and the Clean Water Act, which prohibit discharging petroleum into waterways.
Knowing how to safely refuel your boat protects yourself, your passengers, and the environment.
While the steps might differ slightly depending on your boat's engine type (inboard vs. outboard) and layout (cabin vs no cabin), the main boat refueling best practices remain the same.
Here are 5 safe fueling best practices for boaters:
1. Shut Off Engines and Electronics
This part IS like refueling your car. Just as you must turn off your automobile at the gas pump, you must turn off your boat engine before refueling.
Do not forget to turn off any electrical equipment or fans, as well as extinguish open flames after stopping the engine(s). And remember, while refueling, your boat is a no-smoking zone. Following these rules reduces the risk of fuel vapors being ignited by sparks.
2. Ventilate the Area
Before fueling, close all windows, doors, and openings to prevent fumes from entering the cabin.
After filling your boat fuel tank, you should reopen all the windows and doors you closed to increase ventilation.
Run the bilge blower for at least four minutes if the boat has an inboard engine or enclosed compartments. The ventilation step is not required for boats with outboard motors, which do not have enclosed spaces, but it is still a good idea.
3. Keep Nozzles Grounded
Maintain contact between the fuel nozzle and the tank opening to prevent static buildup. While fueling, never leave the pump unattended.
Once finished, replace the boat fuel cap tightly to prevent vapor leaks.
4. Use Absorbent Pads and Avoid Spills
Ensure that there are absorbent pads around the fill area so that any spills or drips are caught. The best way to clean up spilled marine fuel is to use an absorbent pad. Don't use detergents, as they can cause fuel to sink into the water, harming marine life. You wouldn’t want to endanger Nemo, would you?
Don’t overfill—stop when the tank is about 90–95% full to allow for fuel expansion. You can listen for gurgling sounds, which might indicate a full tank on some boats. However, if you’re refueling in a busy area, it might be difficult to hear this sound. When in doubt, underfill.
5. Check for Leaks and Sniff for Fumes
After fueling, inspect for any leaks and see if you smell fuel vapors before starting the engine. If you detect fumes, ventilate thoroughly before proceeding.
Never restart your engine if you can still smell fumes.
The above tips are good general practices for safe boat fueling, but the refueling process can vary depending on where and how you’re adding fuel to your boat tank.
- Fueling at a Marina Gas Dock
Waves or passing boats can cause some movement when you’re stopped at a fuel dock. Carefully secure your boat to the dock and keep the nozzle in contact with the fill pipe to avoid static sparks. Keep an eye out for drips.
- Fueling at a Gas Station
Stopping at a gas station while your boat is still on the trailer? Level the trailer to make fueling easier and reduce the chance of spills. Make sure you can see the fill pipe clearly—even if that means you need a step stool. Safe fueling is more important than looking cool at the gas station.
Lastly, make sure you’re choosing the right fuel for your engine. Check your owner’s manual if you’re not sure.
- Refueling Portable Marine Fuel Tanks
For boats with removable fuel tanks, you should take them off the boat and fill them on solid ground, like the dock or pavement, to prevent static buildup. You may find it helpful to use a funnel to minimize spills. After filling, secure the portable marine tank back on the boat to prevent it from sliding around as you cruise.
Now go out there and have fun riding the waves!
Bonus boating safety tip: Throughout the season, periodically check to see if your boat’s hose lines, engine fittings, and strainers are all still intact. Fuel lines and marine fittings can wear out; it is important to be aware of when it’s time to replace them.
