Boat and Yacht Carbon Footprint Calculator: Erase Your Emissions and Go Climate Neutral

By Jazmin Murphy | Updated on August 27, 2021

You may not realize how your time floating upon water can affect the environment, but with a boat and yacht carbon footprint calculator, you can determine exactly how much carbon dioxide (CO2) emissions this can produce.

Boating and other leisurely maritime or freshwater activities have become much more common over the years, as aquatic recreational technology advances. Yet, with every new water-bound vehicle zooming across the lakes and rivers of the world, climate emissions rise.

A harbor full of boats at the Galapagos Islands of Ecuador, home to many famous endemic species.

Boats release numerous harmful substances into aquatic and marine environments, including nitrogen oxide, particulate matter, carbon monoxide, and non-methane volatile organic compounds (NMVOCs).

Considering the various gases your vessel produces, going “carbon neutral” isn’t enough.

Unfortunately, getting rid of this single compound won’t spare wildlife from the others’ hazards. Instead, you’ll need to set your sights on climate neutrality. This means calculating your boat’s carbon footprint to determine exactly what you’re pumping into the atmosphere, so you can mitigate your impact effectively.

Boating may not feel as environmentally damaging as driving a car on a highway, but it can be damaging to the health and persistence of global ecosystems. Fortunately, several options are available for you to continue getting out on the water without harming the planet, once you calculate your footprint.

How Much Carbon Do Leisure Boats Pump Out?

Many aquatic vessels are “gas-guzzlers,” just like terrestrial vehicles. As part of the larger “motorized recreation” industry, boats consume 2.2 billion gallons of gasoline every year.1

“Pleasure boats,” along with other fun machines like jet skis, ATVs, and others, account for 1.6 percent of the 143 billion gallons Americans use annually. Plus, because these vessels are built with two-cycle engines instead of four, their emissions levels are “vastly higher” than the amount of fuel they gobble up.1

Statista estimates show that ships and boats in the US produced 40.4 million metric tons (about 44.5 million tons) of carbon dioxide equivalent in 2019 alone. Before then, emissions ranged from a low of about 37.3-47 million tons of carbon dioxide equivalent per year.2

These calculations represent the general category of “ships and boats,” so it’s not exclusive to recreational boating. Instead, the estimates include emissions from commercial shipping fleets as well. With that said, it’s important not to conflate all the emissions in this category to personal boats and yachts alone. To avoid this, you can hone in closer to “vessels in the recreational boating industry.”2

An 8 Billion Trees graphic showing the carbon footprints of various types of marine fuel used in boats and yachts.

Emissions from Recreational Boating

Recreational boating is immensely popular worldwide. As the pastime’s appeal grows, so does its share of greenhouse gas (GHG) emissions. One area that has attracted scientists’ attention in recent years is the Baltic Sea. This location was recently described as highly vulnerable to pollution due to its “low biodiversity and slow water exchange.”

Boats generally release all sorts of gases in addition to carbon dioxide, including:

  • NOx: nitrogen oxide
  • PM: particulate matter or particle pollution, a mixture of airborne particles and liquid droplets made up of several hazardous materials3
  • CO: carbon monoxide
  • NMVOCs: non-methane volatile organic compounds

To make matters worse, emissions from recreational boats tend to be worse than large commercial vessels because of differences in emissions standards between “small recreational boat engines” and “large diesel engines.”

In some cases, small boats are legally allowed to consume two to five times more fuel per power unit than commercial vessels.

Still, this doesn’t mean that a smaller boat will always be worse for the environment than larger ones. Their emissions vary based on their “leisure boat class” designations (specific emissions totals depend on the type of engine):4

Open small boat (OSB, gasoline-powered engine <7kW):

  • 0.2-12.6 g/kg PM
  • 2.5-16.4 g/kg NOx
  • 50.7-322 g/kg NMVOCs
  • 556-1032.9 g/kg CO

Motorboat (MB, engine > 7kW):

  • 0.2-12.6 g/kg PM
  • 2.5-64.1 g/kg NOx
  • 6.3-322 g/kg NMVOC
  • 18.6-539.8 g/kg CO

Large motorboat (LMB):

  • 0.2-12.6 g/kg PM
  • 3.8-31.3 g/kg NOx
  • 6.1-215.5 g/kg NMVOCs
  • 18.6-472.8 g/kg CO

Large motor sailing boat (LMSB):

  • 0.2-12.6 g/kg PM
  • 2.5-34.9 g/kg NOx
  • 6.7-322 g/kg of NMVOCs
  • 18.6-539.8 g/kg of CO

The main differences between all these vessels are the engine types. Out of two-stroke, four-stroke, and diesel engines, two-stroke engines tend to have the most extensive climate impacts, except for the four-stroke engine on an OSB.4

Based on the above data, it’s clear that even sailing boats can negatively affect environmental health. This is why climate neutrality must become a higher priority among boating enthusiasts, many experts argue.

What Does it Mean to be Climate “Neutral?”: Boating’s Impact On Wildlife

The environmental impacts from recreational boating activities extend beyond mere emissions. Researchers cite the main challenges stemming from this sector are:

  • Pollution management
  • Aquatic ecosystem preservation
  • Waterway access

It’s clear that boats’ climate effects are multifaceted. As the engines expel harmful gases into the atmosphere, residual chemicals and direct aquatic and marine habitat destruction eliminate crucial resources for wildlife.

A sea turtle swimming underwater in the Galapagos Islands of Ecuador, with an 8 Billion Trees watermark.

Even boat maintenance activities like antifouling can harm the environment, due to the toxic chemicals used. In addition to the carbon dioxide and other gases released into the environment, this practice can also introduce toxic emissions from paint. This accounts for 67 percent of total emissions for leisure boat owners.5

(“Antifouling” refers to treating the boat’s hull with specialized substances to prevent “fouling.” Fouling is the accumulation of plants and small marine and aquatic animals on a boat’s exterior.)

For these reasons, you must ensure your boating activities are climate neutral and not merely carbon neutral, although that is still a good start.

Some people use the terms “climate neutral” and “carbon neutral” interchangeably. Yet, the two are quite different.6

Working toward climate neutrality means that you’re removing the equivalent of all your boat’s GHGs – not just carbon dioxide – at the same rate that the vessel is releasing them.

On the other hand, carbon neutrality is a much broader goal: achieving a net-zero carbon footprint. In addition to removing harmful gases from the atmosphere, you might also reduce your carbon emissions and offset them too.

Fortunately, innovations in sustainable technology have progressed rapidly. Now, scientists can convert traditional gas-powered boats into hybrid electric vessels, reducing boating enthusiasts’ environmental damage.

Converting Gas-Powered Boats to Hybrid Electric to Save the Climate

For the last few years, scientists have ventured into a new frontier in the field of sustainable technology. Instead of developing technologies to replace current recreational boating equipment, some vessels can be “retrofit,” per se, for a more efficient performance.

For example, in 2015, a small team of researchers successfully converted an 18’ Pursuit 2000 S2 gasoline-powered boat into a hybrid electric boat, or HEB. Specifically, they replaced a nonfunctional Evinrude 225 V6 engine with a battery-powered electric motor.7

The new eco-friendly design is intended for use in rivers and lakes, primarily. The deep-cycle batteries can be solar charged and powered by a hydrogen fuel cell unit as a bonus.

In 2020, another team followed suit, aiming to “[convert] a traditional internal combustion engine-powered leisure boat into an electric propelled type.” This project also focused on battery power, particularly a Battery Energy Storage System (BESS). This reduces fuel consumption and could potentially save boaters money on refueling.8

This represents only the tip of the iceberg of the future of climate-friendly aquatic vessels. Although the study wasn’t meant to initiate commercial production, it does indicate a bright future for prospective boat owners looking to protect environmental health.

What Can the Average Boater Do to Reduce Their Emissions?

Not everyone can afford to convert their gas-powered boats into HEBs, or even has the resources to do so. So, what’s there left to do?9

A 8 Billion Trees graphic showing the cycle of a yacht carbon offset, complete with the client, carbon offset service, carbon offset trading, and a green energy project.

Some actions you can take to reduce your emissions and environmental impact are:

  • Limit the amount of time you operate your vessel at full throttle.
  • Reduce the amount of time your boat idles.
  • Follow the manufacturer’s maintenance recommendations, especially for winter storage.
  • Utilize one of the best carbon offset programs to erase emissions
  • Be careful about refueling – spills can pollute the water or evaporate and worsen air pollution.

You’ll also need to be mindful of your speed while boating. How fast you drive your boat can influence how much you impact the underwater ecosystems, not only because of GHG emissions, but also from noise and even collision risk with aquatic wildlife.

Scientists investigated the relationship between speed and environmental impact in shipping fleets and found that a mere 10 percent reduction in speed reduced overall GHG emissions by roughly 13 percent. This also improved the fleet’s chances of meeting GHG targets by 23 percent.10

By casually cruising along the water instead of racing across the waves, you can reduce your climate impact significantly.

Keep the Waters Clean with Eco-Friendly Choices

Going boating with your loved ones is a rejuvenating experience, but can be much more eco-friendly. Spending time in nature can bring endless fun, as long as you keep the environment as clean as you found it.

Boats introduce more pollutants into natural habitats than people realize, in the form of gases from engine operation and even toxins from anti-fouling paint.

Minor changes like watching your speed while operating your boat and eco-friendly maintenance practices can shrink your carbon footprint before you know it. Even if you cannot invest in more climate-friendly technology right now, you can still do your part to make the world a cleaner place by using a boat and yacht carbon footprint calculator, so you can start reducing your emissions right away.

Learn More About Your Carbon Footprint:


References

1Schildgen, B. (2019, March 30). What is the environmental impact of motorized recreation? Sierra Club. https://www.sierraclub.org/sierra/ask-mr-green/what-environmental-impact-motorized-recreation

2Tiseo, I. (2021, April 23). U.S. ship & boat GHG emissions 1990-2019. Statista. https://www.statista.com/statistics/1120541/us-shipping-ghg-emissions/

3U.S. Environmental Protection Agency. (n.d.). What is PM? https://www3.epa.gov/region1/airquality/pm-what-is.html

4Johansson, L., Ytreberg, E., Jalkanen, J., Fridell, E., Eriksson, K. M., Lagerström, M., Maljutenko, I., Raudsepp, U., Fischer, V., & Roth, E. (2020). Model for leisure boat activities and emissions – implementation for the Baltic Sea. Ocean Science, 16(5), 1143-1163. https://doi.org/10.5194/os-16-1143-2020

5Bergman, K., & Ziegler, F. (2018). Environmental impacts of alternative antifouling methods and use patterns of leisure boat owners. The International Journal of Life Cycle Assessment, 24(4), 725-734. https://doi.org/10.1007/s11367-018-1525-x

6Clarity and Leadership for Environmental Awareness and Research at UC Davis. (2021, July 26). How carbon neutral is different than climate neutral. https://clear.ucdavis.edu/explainers/carbon-neutral-versus-climate-neutral

7Yildiz, F., Coogler, K. L., & Amador, R. (2015). Conversion of a gasoline powered boat to a hybrid electric boat. Journal of Engineering Technology, 32(1), 52-63. https://www.proquest.com/openview/cfd13c6dbb26ed0fdebc07560b680916/1?pq-origsite=gscholar&cbl=32062

8Caprara, G., Martirano, L., & Balleta, C. (2020, June). Preliminary analysis of the conversion of a leisure boat into a battery electric vehicle (BEV). IEEE Xplore. https://ieeexplore.ieee.org/abstract/document/9160492

9Office of Transportation and Air Quality. (2013). Boating pollution prevention tips (EPA-420-F-13-006). United States Environmental Protection Agency. https://nepis.epa.gov/Exe/tiff2png.exe/P100FLQ7.PNG?-r+75+-g+7+D%3A%5CZYFILES%5CINDEX%20DATA%5C11THRU15%5CTIFF%5C00000416%5CP100FLQ7.TIF

10Leaper, R. (2019). The role of slower vessel speeds in reducing greenhouse gas emissions, underwater noise and collision risk to whales. Frontiers in Marine Science, 6. https://doi.org/10.3389/fmars.2019.00505