San Francisco powers its Red & White sightseeing fleet with biodiesel. Seattle’s King County Water Taxi uses biodiesel to move people across Puget Sound.

On the Eastern Seaboard, the Atlantic Cup, which bills itself as the most environmentally responsible sailboat race in the United States, has fueled the event’s Class 40 fleet (for powering to and from the dock) with biodiesel since 2012, and plans to do so again in 2018. In 2015, the Volvo Ocean Race filled boats with biodiesel during the stopover in Newport, Rhode Island, and used the fuel for the shoreside Race Village’s diesel generators. Sailors for the Sea endorses biodiesel’s use as a best practice in the group’s Clean Regattas certification program.

In 2008, skipper and conservationist Pete Bethune used biodiesel to power his wave-piercing power trimaran Earthrace during a 60-day circumnavigation. This year, the tall ship and floating classroom Oliver Hazard Perry filled up with it for a voyage from New England to Cuba.

And yet despite the trend of biodiesel becoming more publicly accepted — and despite eco-minded boaters of all stripes seeking alternatives to petroleum diesel — the renewable fuel still isn’t widely available at yacht club and marina fuel docks.

“It’s a chicken-and-egg situation,” says Robert Morton, a retired marine geologist, offshore ocean racer and a founder of the alternative energy company Newport Biodiesel. “Marinas don’t want to put a tank in because they’re afraid people won’t buy it. Boaters who want to buy it can’t find a marina where they can buy it.”

Pros And Cons For Boaters

Biodiesel is a clean-burning, vegetable oil- or animal-fat-based fuel for use in standard diesel engines. It can be used alone or blended with petrodiesel in any proportion. Biodiesel’s use lags far behind that of traditional fuels; in 2016, the United States used 143 billion gallons of gasoline, 80 billion gallons of diesel and 2.9 billion gallons of biodiesel, according to the National Biodiesel Board. The biodiesel figure represents progress, compared with the 250 million gallons used in 2006, when federal support for its use — in the form of standards and tax incentives — took effect.

Even still, boaters often believe biodiesel is the same as ethanol, Morton says. “Sailors and boaters don’t have a perception of biodiesel,” he says. “They confuse it with ethanol. Biodiesel doesn’t cause the problems that ethanol did with marine tanks and hoses.”

Biodiesel is less toxic than table salt, says Kaleb Little, National Biodiesel Board senior communications manager, adding that the fuel also burns cleaner than petrodiesel and biodegrades as fast as sugar. In his opinion, most people simply don’t know those facts. “Biodiesel blends are an excellent choice for power on the water and have many benefits as a more sustainable option for fueling recreational boats … and other marine applications,” Little says.

“With the commercial biodiesel industry just over a decade old, it is relatively new,” he adds. “Unless you are a diesel user, many consumers don’t understand the difference between gasoline and diesel fuel, much less the difference between biodiesel and other biofuels, like ethanol.”

BoatUS researched biodiesel and ethanol best practices at the request of members and now presents biodiesel as an alternative fuel source. “Environmentally, biodiesel is certainly a good thing,” says Charles Fort, director of the BoatUS Consumer Protection Bureau.

Fort says that the advantages of biodiesel go beyond the environment, including its higher lubricity, which benefits pumps and seals, better engine performance and less soot from exhaust. However, he adds, there are disadvantages, too.

“Biodiesel absorbs more water than diesel, so it’s more likely to foster bug growth than diesel,” Fort says. “We recommend the addition of a biocide [when running biodiesel].”

In addition, because of biodiesel’s organic nature, it’s less stable than petroleum diesel and degrades quicker. “For someone who goes through fuel faster, like a powerboater or sport fisherman, it’s fine,” Fort says. “For a sailor who keeps fuel longer, or for boats that are idle for a while, it’s probably not as good an idea.”

Biodiesel has solvent properties, which means it can break down residue in the tank and fuel system. “That’s good, but it also makes filters clog when you first use it,” Fort says. “In the beginning, you should be prepared to have your system cleaned out and change filters more often.”

And biodiesel congeals in freezing weather, though there are additives to address that, Morton says.

BoatUS advises owners to contact their engine manufacturer to determine whether using biodiesel will void the warranty. Most marine diesel manufacturers authorize the use of 5 to 7 percent biodiesel blends. Mercury Marine, for instance, authorizes the use of 7 percent biodiesel, says product safety manager Pete Chisholm.

The Chicken And Egg Problem

The pros and cons of biodiesel don’t matter much, of course, if boaters can’t find the fuel when it’s time to fill up. “Biodiesel does have a role to play, but it needs marina support,” Earthrace skipper Bethune says. “Boat people may support it, but if the marina doesn’t sell it, it’s hard to see people making the effort to get it.”

Fort agrees. “Because of infrastructure limitations, there’s no way a marina could afford to have a biodiesel and a non-biodiesel tank.”

Tom Rich, a founder of New England Boatworks in Portsmouth, Rhode Island — which this year earned a Clean Marina designation from the state — sees the dilemma from a service yard and marina perspective.

“About six years ago we were approached,” he says. “We were going to install a tank so we could pump a biodiesel blend. At the time there were problems, and we had no demand, so we decided against it. Also, as it gets colder, biodiesel gels up. Owners were concerned about putting it in their boats. Sailboats don’t use fuel as much as powerboats. They have a 20- gallon tank, and if they don’t use the fuel, they tend to leave it in there. If the technology improves, maybe it’s viable.

“We follow all requirements for fueling,” Rich adds. “We’d have to have a separate tank. At the time, everybody liked it. It put out a nice, sweet smell, and it was biodegradable. But we didn’t know about performance. We were also concerned about the regulations for handling it. How big a problem is it for a marina? I need to know the regulations. It certainly is something we’d like to do if it’s going to have demand and be good for the environment.”

The National Biodiesel Board is continuing to push the fuel for boaters. “It has been clearly demonstrated that biodiesel works in marine diesel applications,” Little says. “Biodiesel is serving as a cleaner-burning, more environmentally friendly option for the marine environment. It is important for boaters to do their part to ensure future generations can enjoy the water the same way that they do.”

Morton, who has attempted to persuade yacht clubs to make biodiesel available on their docks, says infrastructure is a major hurdle. “Perception and infrastructure,” he says. “My goal is having everybody — marinas and the world — using B20 [20 percent biodiesel], at least in summer.

“Everybody talks about how we’re reducing emissions because we’re using natural gas,” he adds. “If we used B20 it would be so much better. It reduces emissions, on average, 85 percent, compared to petroleum diesel. It’s the best fuel out there in terms of greenhouse gas emissions.”

This article originally appeared in the July 2017 issue.