There has been so much attention paid to designing environmentally friendly cars

There has been so much attention paid to designing environmentally friendly cars. Is there a similar effort to replace gas-guzzling boats?

—Brita B., via e-mail

The U.S. has been regulating fuel economy and emissions in cars and trucks for decades but got a late start addressing similar issues with boats. In 1996, though, recognizing a growing problem of boat engine pollution, the Environmental Protection Agency (EPA) issued new rules to “bring forth a new generation of marine engines featuring cleaner technology and providing better engine performance to boat owners.”

Even small quantities of fuel and exhaust discharged by boats can disrupt the balance of nutrients, oxygen and clean water in both freshwater and marine ecosystems. Indeed, the cumulative effect of millions of inefficient motorboats plying our waterways has been devastating to marine life and our water supplies. Under the new EPA regulations, which will phase in over the next 30 years, new marine engines will burn gas much more efficiently and generate much less pollution than most models out on the water today.

According to the EPA, traditional two-stroke boat engines waste significant amounts of gasoline and oil, spilling as much as 30 percent of their fuel into the water and air either unburned or partially unburned. In the water, unburned hydrocarbons increase concentrations of benzene, methyl tertiary-butyl ether (MBTE) and other toxic substances that pollute water ecosystems. In the air, they help form smog, which causes a host of health problems and disrupts visibility everywhere from our cities to our national parks.

Those looking to buy a boat today should choose one with a four-stroke or direct fuel injection (DFI) two-stroke engine. These pollute about 75 percent less than their traditional two-stroke predecessors and use as much as 50 percent less gas and oil. They cost more than traditional two-stroke engines, but owners soon make up the difference in fuel and oil savings. They are also easier to start and maintain, and are quieter.

New generations of electric boat motors are also coming on line, and promise to significantly cut pollution if adopted widely. Wooden, sport and leisure boats are now all available with electric engines that are quite comparable to traditional engines in performance and looks. They are also non-polluting, quiet and can cruise where gas motors are not permitted. Some leading makers include Beckman, Budsin, Cobalt Marine, Electric Launch, Duffy, Electracraft, Griffin Leisure, Pender Harbour and Spincraft.

The only catch is that the energy that powers the batteries for electric boats most likely comes from a coal-burning power plant that spews mercury, carbon dioxide and other pollutants into the skies and waterways. A handful of manufacturers—such as Australia’s Solar Sailor and Canada’s Tamarack Lake—now make solar-powered or solar-assisted electric boats to help overcome this environmental hurdle.

Of course, the ultimate energy source for any recreational activity is elbow grease. But for those who need more than a canoe or kayak to get around, Nauticraft hybrid boats employ human pedal power to augment a small electric motor. And the Italian-made Shuttle Bike puts a new spin on pedal boats: Owners affix two inflatable pontoons to their mountain bikes, and they can then pedal around their local lake or harbor.

CONTACTS: EPA: Shipshape Shores and Waters: A Handbook for Marina Operators and Recreational Boa