Bill Taylor of Hampton Hills was cruising down the lake with 10 family members aboard his boat when it happened.

"The engine had been running fine. All of a sudden, it sputtered to a stop and refused to start again," he recalled. "We waved down a fireboat that happened to be returning from a call at the 4-H Center and got a tow back to our dock."

What happened to Taylor is not uncommon. His boat's outboard fuel lines had become clogged -- most likely from an adverse reaction to gasoline containing ethanol.

"Next day I replaced all the fuel lines, and that solved the problem," said Taylor.

Ethanol, a type of alcohol, is a solvent, degreaser, cleanser and antifreeze that makes up 10 percent of much of the fuel now being sold. Beginning later this year, it will be a federally mandated additive in all gasoline, including what is sold at marina pumps.

Ethanol is highly "hygroscopic" -- it absorbs water. In fact, fuel that contains ethanol attracts and rapidly absorbs 50 times more water than fuel that doesn't. Couple that with summer humidity, a marine environment and boats that sit idle for long periods (allowing condensation to form in undisturbed fuel tanks), and you have a recipe for water-in-gas problems -- fuel starvation, rough running and poor performance.

As Taylor and his on-board guests found out, ethanol can result in engines that just quit running.

Stacey Pickeral, a mechanic at Union Hall Marine, often works on older boat engines, ones most likely to be affected, and has seen about eight repair cases that he attributed to the additive.

"Mostly carbureted 2-stroke outboards," he said. "Hard starting, loss of power, some won't run at all ... usually due to carburetor diaphragms or fuel lines that have deteriorated."

He said typical repair for an engine that's been stricken takes three hours and costs $400, parts included.

"Using fuel-drying additives just adds to the problem, said Dale Runyon, owner of BaySide Marina on Becky's Creek. "They're ethanol-based and serve to increase the concentration."

He explained that the "gunk" that ethanol cleanses from fuel systems can easily plug fuel lines, filters, injectors and fuel pumps in stern drive engines. Confirming Taylor's experience, he added: "Some older fuel lines and primer bulbs suffer breakdown of the inside walls," he said, illustrating by cutting open a section of fuel hose from a recently repaired outboard that was lined with a sticky black tar-like substance.

"Like clogged arteries," he said, easily removing a slimy gob with the tip of his knife.

Research at the National Marine Manufacturers Association (NMMA) has found that some older gasoline blends contained a compound called MTBE that, when mixed with ethanol, produced a black sludge. NMMA suggests not mixing old and new gasoline.

Runyon said he believed one reason boats are more susceptible to ethanol-induced problems as opposed to cars is the tendency for heat to build up in their engine compartments.

"Road vehicle engines get more cooling from passing outside air," he explained.

Propulsion systems in newer boats and PWCs are designed to accommodate alcohol-based fuels with no problems. But some of the plastic/butyl/composite hoses, O-rings and gaskets found in older models are less alcohol resistant.

Changing fuel filters regularly is a good precautionary measure. Some boaters even add a second filter in their systems for increased protection.

Jim Barron, who's been technical editor at Trailer Boats magazine for some 28 years, noted that most boat fuel systems are relatively immune to ethanol degradation, though those with fiberglass fuel tanks are an exception.

Under the Sept., 2008, heading of "E10 Fuel Concerns," he wrote: "Of greater concern is ethanol's affinity for water. And because ethanol acts as a solvent that loosens tank deposits, you may suffer the double whammy of particulates and water collecting at the bottom of your tank and then entering the engine, resulting in clogged filters and poor performance. A number of additives, including Sta-Bil's Marine Formula Ethanol Treatment (www.sta-bil.com) and Star brite's Star Tron (starbrite.com) are available to help ward off potential problems."

Non-ethanol gasoline on decline

Gasoline purchased roadside is increasingly likely to have up to 10 percent ethanol blended in. One local distributor said roughly 50 percent of its stations have made the changeover, which requires a thorough cleansing of the underground storage tanks to remove accumulated contaminants that could get freed up from the cleansing and water-grabbing properties of the additive.

A quick check of area marinas showed that most all shore-side gas pumps still dispense ethanol-free gasoline, at least for now. Roy Enslow, owner of Bridgewater Marina, said he is not aware of any that have made the changeover to gasoline containing the additive.

"I plan to hold off as long as I can," said Enslow.

"We don't want our customers to have any problems, so we'll stock pure gas as long as we can get it," said Tom Buck, owner of Mitchell's Point Marina. "But our supplier -- Glenwood Fuel in Huddleston -- can't say for sure how long that will be."

As for the expensive storage tank cleanout required at changeover: "We're ready to do it when we have to," Buck said.

Don Thacker of Huddleston's Central Oil, whose company still delivers alcohol-free gasoline to Magnum and Indian Point marinas, agreed that the total replacement of conventional fuels with ethanol blends is coming.

"The phase-in is part of the nation's effort to become less dependent on oil," said Thacker. "Ethanol is high octane and burns cleanly. Using it just takes some extra care with storage."

Experts seem to agree that the safe storage life of ethanol-blend fuels is shorter because of their water-absorbing and corrosive qualities, with 90 days being the recommended maximum.

Ethanol-gasoline users are urged to follow the practice of draining or fully topping off tanks for winter storage since tanks prepared in this way produce less condensation.

Other small engines that experience long periods of non-use -- lawn mowers, leaf blowers and chain saws, for example -- also benefit from being stored dry.