What does the future hold for sustainable boating?

Sustainable boating means minimizing your impact on the marine environment as much as possible. Reducing fuel consumption, properly disposing of waste, and using eco-friendly products are ways to be more sustainable on the water. Watching out for wildlife and avoiding marine vegetation like seagrass and living coral areas are also critical for reducing human impact when boating.

According to the experts we spoke to, pollution, acidification, hypoxia, and habitat destruction are just a few issues currently impacting our oceans and waterways. The good news is that historically, we've had great success solving problems on the water through a combination of policy, technology, and individual stewardship. Our experts see that same combination helping us as we face new challenges in the future.

Key takeaways:

• Our oceans, rivers, and lakes are under intense pressure due to human impact and warming waters. Still, the potential for innovative solutions and new policies gives hope for a better future.
• Sustainable boating is an important part of conserving marine life and protecting the environment from additional harm
• Boaters can practice clean boating and good environmental stewardship to help conserve our waters so we can enjoy them long into the future

Who we spoke to:

Sustainable boating successes through policy

The creation of the Environmental Protection Agency and the passage of the Clean Air and Clean Water Acts, followed by the Clean Vessel Act (CVA) in 1992, have had a significant impact on promoting sustainable boating practices and reducing pollution, according to our experts.

Waste dumping stopped a major boat pollution problem

The CVA has transformed many bodies of water by changing the way recreation boats discharge waste, says Dennis Nixon, who recently retired as a professor at the University of Rhode Island and the RI Sea Grant. Before the CVA, he says, boats could dump sewage directly into the water, a major way recreational boats were causing water pollution. As an avid sailor who spends as much time as he can on the water, Nixon has seen the positive effects firsthand of stopping that practice, holding up Block Island in Rhode Island, "a jewel of the Northeast," as a prime example.

The Inner Pond is a body of water that would see a thousand boats anchored during Fourth of July weekends back in the 1970s, he says. "I was one of them — in an old wooden boat — and all we had was an over-the-side discharge through the hull. And you couldn't swim in the pond — shellfishing was closed for the summer."

Since then, Nixon says CVA regulations have funded pump-out stations and encouraged boats to be redesigned with holding tanks, dramatically reducing waste in the water.

Today, Block Island's Inner Pond "looks like the Caribbean," according to Nixon. "You can see 20 feet to the bottom, and people are allowed to commercially shellfish there in the pond, which is adjacent to a mooring field. That would have been unheard of, but because they enforce the no-discharge rules so vigorously, the water is beautiful now."

Improved engine design reduced boat pollution emissions

Jeff Wasil at the NMMA says the Clean Air Act was a game-changing policy for the waterways, too. CAA regulations ushered in improved boating sustainability by targeting recreational boat engines with a 1997 emissions compliance rule.

"Prior to that, they were not regulated at all," he says. For decades, standard boat engines were conventional two-stroke engines, the same as some lawn and garden equipment. "When you started it up, it was like a tire fire," he says, spewing smoke and fumes into the air.

Wasil started his career at an outboard motor manufacturer and oversaw compliance with the new regulations, which he says made a measurable difference. He also credits another CAA regulation with reducing evaporative emissions and modernizing boat manufacturing to make boats much cleaner. It's now standard when fueling a boat gas tank that the fuel automatically shuts off when the gas tank is full. Without evaporative emissions controls, gas could — and often did — overflow and spill into the water, says Wasil. Another significant improvement was adding carbon-capture canisters and pressure relief valves to prevent fumes from escaping.

"In my career, we've reduced emissions by over 90% relative to conventional carburetor engines," he says. "And we've increased fuel efficiency by over 40% in the last ten years."

What were once game-changing innovations are now expectations for boaters, who probably couldn't imagine dumping their waste into the water, Nixon says, adding that boaters enjoy a unique perspective on environmental issues because they see the direct impact of pollution when boating.

"The more people we get on the water, the more committed environmentalists we are gonna get," says Nixon, who sees plenty of room for more sustainable boating practices and innovations.

How water pollution affects marine life

Although boating practices and manufacturing changes have made measurable improvements in marine habitats, our experts say we still face growing environmental challenges affecting our waterways. Water pollution can affect marine life in myriad ways.

Plastic and nutrient pollution are big concerns for Shelley Brown in Rhode Island because they harm marine life by reducing oxygen in the water and by increasing plastic particles that can be mistakenly ingested.

Brown received her doctorate in microbial ecology, researching the impact of hypoxia, or low oxygen conditions, on sediment microbes in the Narragansett Bay. Human activity on land — like farming, fertilizing, and sewage discharge — adds nitrogen and other nutrients to the water, which can cause large algal blooms. When the algae dies and decomposes, under certain conditions, oxygen levels can plummet, creating toxic conditions for marine life and resulting in mass fish kills and other issues.

"I learned a lot in that process," she says. "But the main takeaway is that what we do on land impacts oceans on a global scale."

In Florida, Joshua Patterson is also spreading awareness and taking action to reduce negative human impact on the marine environment. The issue he's focused on is seagrass scarring, which happens when boat propellors cut through beds of seagrass vegetation, leaving behind scars that can take years to heal.

Seagrass is a crucial habitat and food source for marine life, he says, that also buffers against ocean acidification by storing carbon. Its health can also be damaged by nitrogen in the water due to runoff. If habitats are damaged, marine life will inevitably be harmed, too.

As a research scientist and associate professor at the University of Florida, Patterson's specialization is using aquaculture to restore and protect seagrasses, coral reefs, and fishery habitats. He says environmental restoration has had great success in Tampa Bay, where seagrass had been declining for years.

"Back in 2015 and 2016, they had recovered back to 1950s levels, which is incredible — and that had largely been achieved by reducing nitrogen inputs into the bay," he says.

Patterson considers his work one component of conserving ocean health and protecting marine life. "What we're doing is a tool in the toolbox," he says. "Not the entire answer."

Sustainable boating through cutting-edge manufacturing

Another tool in the toolbox for eco-friendly boating is greener boat manufacturing. Jeff Wasil says electric boat engines have been a big talking point for decarbonizing the boating industry, an important aspect of sustainability. For manufacturers, it's been unclear if electric boats would achieve decarbonization goals, so the International Council of Marine Industry Associations (ICOMIA), of which NMMA is a member, conducted a comprehensive research study to examine the issue.

Wasil says the study was important since carbon output for manufacturing electric propulsion is about 50% higher than combustible engines. For cars, the emissions saved can be worth that cost, but boat manufacturers weren't convinced it could save enough in emissions to offset the higher costs.

When evaluating those costs and savings, the big difference between cars and boats is the total lifecycle — from mining materials to the vehicle's usage, says Wasil.

"You're basically going to drive a car for 150,000 miles before it reaches the end of its useful life. Boats are operated between 35 and 48 hours a year, so very, very low usage." He says the automotive industry stands to reduce emissions by about 50 to 70% with electric cars — a significant reduction.

Boats, on the other hand, are not only used much less, but they require more power to move through the water, says Wasil. He adds that boats need bigger batteries, making them even heavier, which then increases energy demands. "You can't necessarily overcome that," he says. "There's no way to match the energy content or the range of a gasoline boat with a battery-powered boat. So that's something that's been very challenging."

Despite the challenges, Wasil sees electric boats as a promising solution for certain uses, like a ferry that moves passengers on a daily schedule. In that case, it could make sense because they could measure the output and manage the boat's energy needs effectively.

Boaters and marinas lead the way on sustainable boating practices

While electric boating may not be a fleet-wide solution, Nixon is a proponent of electrification for different types of recreational boating and sees eco-friendly alternatives being adopted by boaters more and more.

He's noticed boaters replacing generators with solar panels to run their liveaboard boats and big sailboats being outfitted with cutting-edge electric motors from Torqeedo and Mercury. "That's the technological change we're seeing," says Nixon. "These are being built as features into new boats, and old boats are being retrofitted. It's been a really great, positive change."

Nixon has worked with marinas on eco-friendly practices for years. He founded the International Marina Institute (now part of Assoc. of Marina Industries), which runs the Clean and Resilient Marina Program.

For marinas, he says, having pump-out stations, a plan for fuel spills, and a way to mitigate stormwater runoff from parking lots are some of the best ways to promote sustainable boating.

Green practices can be as simple as handing an oil diaper to boaters when they gas up to prevent gas from dripping into water or putting a recycling bin on the dock for soda and beer cans, Nixon says. His marina put in a recycling bin and has collected tons of aluminum from that simple change. "That's trash that doesn’t end up in the ocean," he says.