We all share the same water, so being a responsible boater is everyone’s job. BoatU.S. explains how to do your part.

It’s easier than you think to accidentally turn what should be a routine chore at the fuel dock into a first-class mess. Part of being a sensible, responsible boater is ensuring that fuel tanks are filled correctly and no fuel is spilled into the water, which can have significant consequences for aquatic life. Here are 10 simple ways to avoid this issue.

Filling fuel tanks requires careful procedures. Even if a fuel-fill nozzle has a lock-off device, don't use it. By the time the nozzle catch has tripped and stopped the flow of fuel, you may have already sent a fair amount of fuel onto the deck and into the water. This malady is most often caused by "burping," which is the result of air trapped in the tank or the boat's fill hose. It escapes through the fuel fill, bringing fuel with it.

The Clean Way Fuel Fill is an example of a product that helps avoid fuel spills at the pump. In the event of fuel burping back through the filler, excess fuel is directed upward into the device, where downward sloping baffles lead overflowing fuel back into the tank.

Another method is to wrap an oil absorbent pad or heavy absorbent sock around the fuel fill nozzle to catch any blowback or errant spills. And always keep ample oil-absorbent pads within quick reach should something go wrong. An internet search will reveal various products to help prevent spills, but always look for testing reviews and do some testing yourself to be sure that any product does as advertised in your situation.

Fuel in the bilge

Not all oil pollution occurs while filling the boat with fuel. Bilge water often contains oil, grease, and fuel. To prevent this oily water from being pumped out of the boat by the bilge pump, consider placing oil-absorbent sheets under inboard engines. A couple of oil absorbent bilge socks or sausages in the lowest part of the bilge close to the bilge pump pickup (but not interfering with the pickup or switch) will go a long way to preventing dirty bilge water from polluting waterways.

At least once a year, check all fuel hoses for cracks and loose connections that may cause leaks, replacing any that may be suspect. ABYC standards stipulate that all fuel fill hoses should be double-clamped, so ensure that all hose clamps are in place and well tightened.

In sum, preventing spills is up to all of us. Using a little common sense and some basic preventive measures, we can keep our waterways clean for all. But no matter which “devices” or techniques you use, “CAUTION” is always in order. With fuel, oil or grease, it doesn’t take much on a boat for something to go wrong causing a sheen on the surface.

10 ways to prevent fuel spills

1. Make sure that you’re putting fuel into the correct tank. GEICO | BoatU.S. receives claims each year from someone pumping fuel into a rod holder or water tank. 
2. Fill tanks only to about 95% capacity to allow for expansion and sloshing as the boat moves.
3. Do not top off the tank. The boat’s movement may cause fuel to leak from the tank vent, causing pollution.
4. Use absorbent sheets or pads around the fuel pump nozzle while transferring it from the dock to the boat and while filling to prevent splashes marking boat decks and leaking into the water.
5. Listen carefully. It’s often possible to hear when the fuel is getting closer to the top of the tank.
6. Hold (or have someone else hold) a highly absorbent rag or fuel absorbent pad at the fuel tank’s air vent to absorb any spillage from the vent. Or consider purchasing a fuel-vent collection device that sticks on the outside of the boat with suction cups and will hopefully collect any fuel that happens to find its way out of the vent. But if there is ANY question of this type of device adhering to the hull, have someone hold it in place.
7. Consider installing a whistle in the fuel-vent line, designed to make noise as long as fuel is flowing. As soon as the tank is full, the whistle stops, and you know it’s full.
8. Don’t let the higher pump speed catch you unaware. Many pumps at fuel docks fill at a much quicker rate than those at the local gas station to allow boats that often have large fuel tanks to fill faster. Also, even if a fuel-fill nozzle has a lock-off device, don’t use it. By the time the nozzle catch has tripped and stopped the flow of fuel, you may have already sent a fair amount of fuel onto the deck and into the water.
9. Regularly check your fuel system for leaks. Not only is this a fire and explosion hazard, but if fuel leaks into the bilge, it may be pumped over the side by the bilge pump.
10. Replace the gas cap after fueling, and maintain the gasketing around the cap.

Fuel In The Bilge

Not all oil pollution occurs while filling the boat with fuel. Bilge water often contains oil, grease, and fuel. To prevent this oily water from being pumped out of the boat by the bilge pump, consider placing oil-absorbent sheets under inboard engines. A couple of oil absorbent bilge socks or sausages in the lowest part of the bilge close to the bilge pump pickup (but not interfering with the pickup or switch) will go a long way to preventing dirty bilge water from polluting waterways.

BoatU.S. recommends, at least once a year, check all fuel hoses for cracks and loose connections that may cause leaks, replacing any that may be suspect. ABYC standards stipulate that all fuel fill hoses should be double-clamped, so ensure that all hose clamps are in place and well tightened.

What To Do If It Happens

By law, any oil or fuel spill that leaves a sheen on the water must be reported to the U.S. Coast Guard National Response Center by calling (800) 424-8802. If it happens, do not (as some have erroneously done) try to use detergents of any kind to disperse spilled fuel. This does more harm than good. It only breaks down the fuel floating on the water into smaller particles, making it much harder to clean up and more toxic to marine life. According to the Environmental Protection Agency (EPA), one pint of fuel spilled into the sea or lake creates a toxic oil slick that can cover 1 acre, larger than a football field.

Pro Tip

If you have a gasoline inboard engine, run the blower for at least 4 minutes — more is better — after filling the tank to disperse explosive vapors before attempting to start the engine. The blower and its switch should be ignition-protected and designed for the purpose.

BoatU.S. Foundation

The BoatU.S. Foundation for Safety & Clean Water is a 501(c)(3) nonprofit organization dedicated to keeping boating safe and clean. It is independently funded by donations from BoatU.S. members and grants. Visit BoatUS.org to learn more.

The Clean Way Fuel Fill is one of several products that help prevent fuel spills.

This article was reprinted with permission from BoatU.S. Magazine, flagship publication of the membership organization Boat Owners Association of The United States (BoatU.S.). For more expert articles and videos to make your boating, sailing, or fishing better, visit BoatUS.com.