San Francisco’s Red & White sightseeing fleet runs on biodiesel, and Seattle’s King County Water Taxi uses biodiesel to ferry passengers across Puget Sound.
Along the Eastern Seaboard, the Atlantic Cup — which promotes itself as one of the United States’ most environmentally responsible sailboat races — has fueled its Class 40 fleet with biodiesel for dock and transit use since 2012, and planned to continue that practice in 2018. In 2015, the Volvo Ocean Race used biodiesel for boats and for shore-side diesel generators during the Newport, Rhode Island stopover. Conservation group Sailors for the Sea endorses biodiesel as a best practice under its Clean Regattas certification.
In 2008, skipper and conservationist Pete Bethune powered his wave-piercing power trimaran Earthrace on biodiesel during a 60-day circumnavigation. More recently, the tall ship and floating classroom Oliver Hazard Perry topped off with biodiesel for a voyage from New England to Cuba.
Despite growing public acceptance and increasing interest among environmentally minded boaters, biodiesel remains relatively uncommon at yacht club and marina fuel docks.
Pros and Cons for Boaters
Biodiesel is a cleaner-burning fuel made from vegetable oils or animal fats that can be used in standard diesel engines either neat or blended with petroleum diesel in any proportion. Adoption is still small compared with conventional fuels: in 2016 the United States consumed about 143 billion gallons of gasoline, 80 billion gallons of diesel and 2.9 billion gallons of biodiesel, according to the National Biodiesel Board. That 2.9 billion figure marks growth from roughly 250 million gallons in 2006, when federal standards and tax incentives began encouraging biodiesel production and use.
Many boaters confuse biodiesel with ethanol and assume it causes the same tank and hose problems, says Robert Morton, a retired marine geologist, offshore racer and founder of Newport Biodiesel. “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.”
Kaleb Little, senior communications manager at the National Biodiesel Board, notes that biodiesel is less toxic than table salt, burns cleaner than petroleum diesel and biodegrades rapidly. “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,” he says. He also points out that because the commercial biodiesel industry is relatively young, many consumers don’t yet understand the differences among gasoline, diesel and various biofuels.
BoatUS researched biodiesel and ethanol best practices at members’ request and now includes biodiesel as an alternative fuel option. Charles Fort, director of the BoatUS Consumer Protection Bureau, says the benefits include higher lubricity for pumps and seals, improved engine performance and reduced soot emissions. Yet he also highlights practical downsides.
“Biodiesel absorbs more water than diesel, so it’s more likely to foster bug growth than diesel,” Fort says. He recommends adding a biocide when operating on biodiesel. Because biodiesel is organic, it is less stable than petroleum diesel and degrades more quickly; that makes it a good fit for users who consume fuel rapidly, such as powerboaters, but less attractive for sailors who store fuel for long periods. Biodiesel’s solvent properties can clean tanks and fuel systems, which is beneficial, but that cleaning can clog filters when biodiesel is first introduced, so owners should be prepared to change filters more often initially. It also gels in very cold weather, though additives exist to mitigate this.
Boat owners should consult their engine manufacturer about warranty implications. Many marine diesel manufacturers permit small biodiesel blends—generally in the 5 to 7 percent range. For example, Mercury Marine authorizes the use of a 7 percent biodiesel blend, according to product safety manager Pete Chisholm.
The Chicken-and-Egg Problem
Even when boaters want biodiesel, accessibility is a barrier. “It’s a chicken-and-egg situation,” Morton says. “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.”
“Biodiesel does have a role to play, but it needs marina support,” Bethune adds. “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 that infrastructure and the costs of separate storage make it difficult for marinas to offer both biodiesel and petroleum diesel.
Tom Rich, a founder of New England Boatworks in Portsmouth, Rhode Island, which earned a Clean Marina designation this year, describes the dilemma from a service-yard perspective. About six years ago the yard considered installing a tank to dispense a biodiesel blend, but at the time demand was low and there were operational concerns. “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,” Rich says. He also cites uncertainty about handling regulations and the need for a separate tank as obstacles. “It certainly is something we’d like to do if it’s going to have demand and be good for the environment,” he adds.
The National Biodiesel Board continues to advocate biodiesel for marine use. “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 worked to persuade yacht clubs to make biodiesel available at docks, emphasizes both perception and infrastructure as the main barriers. “My goal is having everybody — marinas and the world — using B20 [20 percent biodiesel], at least in summer,” he says. “Everybody talks about how we’re reducing emissions because we’re using natural gas. 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.