Parker Engine Mobile OE: Racor Products Blog & Information - North America

An Ounce of Prevention: How to prevent & clean up fuel spills on the water.

Capt. Vince Daniello: Fueling accidents account for many marina spills. Avoid distractions such as taking calls (a safety hazard itself) while fueling your boat.


In the water, they look like shimmering rainbow patterns that to the unaware might appear beautiful. They are not. Those tie-dye patterns are the result of foul-smelling fuel from spills or oil from bilges that plague busy marinas. “Any discharge of oil or fuel, even a drop, that creates a sheen, sludge or emulsion on the surface or beneath the water is considered harmful and requires a call to the National Response Center,” says Chief Luke Potter, who heads the U.S. Coast Guard Sector Boston’s Incident Management Division.

Fortunately, it’s easy to prevent or reduce a spill with products that make fueling and bilge discharge cleaner. We talked to experts about oil spill reporting, picked up tips to head off common causes, and learned how boat owners can lessen the impact if they do spill fuel or oil.

Stopping the Spills

For recreational boaters, the most obvious source of fuel spills occurs at the fuel dock. There are tools to prevent these minor spills. To catch fuel before it hits the water, Centek Industries ( makes a FuelKleen collar that surrounds a fuel nozzle with loose granular filler inside a cloth bag, which contains lots of Mycelx-treated surface to absorb fuel. The Clean Way Fuel Fill from Scandvik ( seals around most fuel nozzles and also seals atop most boats’ fuel fill. The clear funnellike top lets air out while baffles divert fuel back down into the tank.

For boats that prove difficult to fill, check tank vents. Make sure the vent fitting hasn’t been clogged by wax, dirt or insect activity. Then check the hose.

If fuel backs up through the fill, look for a kinked vent hose or clogged vent fitting. Also try shifting weight while fueling so the vent fitting is at the highest point in the tank.

“The vent hose should loop up and back down right where it enters the boat,” says Tim Moore, a service technician at Goodhue and Hawkins Navy Yard on New Hampshire’s Lake Winnipesaukee ( This helps keep water out of the tanks. “From there, you want a nice smooth run down to the tank,” he adds. “Fuel puddles in any low spots. When you’re filling, air flowing through that vent hose pushes those puddles right out of the vent and into the water.”

Installing Racor’s Lifeguard fuel/air separator will trap fuel but release air from the vent line (LifeGuard Fuel-Air-Separators). (LG100 & LG50).

Bilges are another common pollution source. “So many boaters think it’s OK to pump nasty, oily bilgewater into the environment,” Potter says. Head off spills with oil-absorbing towels beneath engines and oil-absorbing bilge socks that skim bilgewater. (Both are available from Star brite.) Centek’s BilgeKleen filter system passes a pump discharge hose through a Mycelx-treated filter.

“It’s really intended to polish bilgewater,” says Bill Arwood of Centek. Note that it’s not wise to install anything in a bilge-pump line without an unfettered backup pump nearby.

Fuel leaks are also a fire hazard. “Most filter fittings are tapered pipe thread. They’ll crack if overtightened,” warns Moore. Leaky filters typically suck in air and cause engine issues, Moore says, and some drip fuel when the engines are off.

Cracked fuel lines also leak, but leaky tank-top fuel gauge senders are more common. “When you fill the tank to the top,” Moore says, “the sending unit is under pressure. It can leak a lot of fuel into the bilge.” Fortunately, a new gasket and sometimes larger-diameter screws quickly fix most sender leaks.

Sunken boats also cause many spills. “My boat won’t sink,” you say. It happens more often than you’d think, typically while a boat is tied up unattended in its slip. “It seems boats often sink at the dock after someone has been working on bilge pumps or through-hull fittings,” P