Carbon Offsets for Boats: Erase the Ecological Footprint of Your Watercraft

Georgette Kilgore headshot, wearing 8 Billion Trees shirt with forest in the background.Written by Georgette Kilgore

Carbon Offsets Credits | February 21, 2024

A photograph of the acidified ocean in Panama City Beach, FL (Redneck Riviera) with cloudy skies, aqua green hues, and beach sand in the foreground.

Carbon offsets for boats and other watercraft are vital to reducing CO2 boat emissions that are linked to climate change, and that are killing coral and destroying ocean life.

Figure up your boat emissions right now:

Now, hop on board as we set sail on a voyage to learn what Carbon offsets are, how to calculate your specific watercraft’s carbon footprint, and why taking action has never been easier.

Want to Skip The Voyage and Dock Now? Calculate all your boat’s and lifestyle emissions here!

All Combustible Engines Generate CO2

Every combustible engine generates carbon emissions (CO2). This invisible, odorless gas is released when substances that contain carbon, such as gasoline, coal or wood, are burned. So, when you burn a gallon of gasoline in any type of engine, it releases the same amount of CO2, regardless of the machine (lawnmower, car, boat, or other).

Factors such as drag, weight, acceleration, and others all contribute to fuel efficiency, but they don’t impact the amount of CO2 released per gallon, which is about 20 pounds of CO2, according to the EPA.

But the good news is, like all emissions, you can offset the dangerous gasses generated by your boat by funding projects that either eliminate it from the atmosphere or sequester it through carbon sinks. Carbon sinks are areas of the planet that ‘store’ the normal amounts of CO2 in the air. The ocean is a huge one, and vegetation (largely trees) are another. However, too much CO2 is causing problems like climate change and ocean acidification. Fossil fuels used for transportation – like the fuel in your boat – are typically the biggest single source of CO2 emissions in the United States.

What are “Boat” Carbon Offsets and How are They Different?

Scientists have known that using fossil fuels wasn’t sustainable for years – the question was what we should do about it. Developing new sources of energy was proving to be both challenging and exceedingly slow. A few decades ago, scientists determined that since we couldn’t stop using fossil fuels, the best way to deal with the CO2 emissions was just to recapture the CO2 elsewhere. This is known as a carbon offset.

Boat offsets are just like any other carbon offset. Essentially, you’re purchasing the carbon capturing “services” of a company to sequester the same amount of CO2 that you’ve released into the atmosphere. This doesn’t have to be done directly – the environment doesn’t care if a pound of CO2 is released in Japan but offset by a tree planted in Europe, because the atmosphere is constantly mixing.

This was one of the key tenets of the Kyoto Protocol, one of the first major treaties to combat Global Warming. So, you can offset the carbon you generate in the U.S. by planting trees in the Amazon.

The Ocean’s Role in Keeping the Atmosphere Balanced

Interestingly, the ocean plays a key role in keeping atmospheric CO2 in balance by absorbing about 30 percent of the CO2 that is released into the atmosphere (from all sources). This gigantic carbon sink is working overtime to get the excessive amounts of CO2 out of the atmosphere.

But, when carbon dioxide is absorbed by seawater, chemical reactions occur that increase the acidity of the water through a process known as ocean acidification. This increase in acidity makes it more difficult for corals to grow and stay healthy. Corals are the marine equivalent of forests. They provide a foundational ecosystem. Ocean acidification destroys them, and also prevents many animals from creating shells.

Calculate Your Boat’s Carbon Emissions (Reduce Carbon Emissions and Save $$$ at the fuel Dock)

Getting the exact amount of your boat emissions is easy. You just need to use a boat carbon calculator. However, there are some standard rules you can apply to figure out your boat emissions, depending on the sort of engine you have, how many hours you spend on the water, and other factors that contribute to the CO2 your boat makes.

How Much Carbon Dioxide Does a Boat Produce?

The amount of CO2 you boat generates will depend on various aspects such as size, average cruising speed, fuel efficiency and type of fuel. So, the best way to calculate your boat’s carbon footprint is to keep track of the amount of fuel you use.

How Much CO2 Does a Boat Emit Per Nautical Mile?

Nautical mile is not really an accurate way to measure your boat’s carbon emissions, because fuel efficiency plays a key role in how much CO2 is generated per mile. Moreover, the size of the craft will impact the CO2 emissions. Incidentally, carbon neutral boats do exist, but at this point, are impractical for individual consumers.

What are CO2 Emission from Fuel Type?

Generally speaking, the following boat fuel types have these carbon emissions:

A graph showing the pounds of carbon emissions produced by boats with different fuel types. Diesel produces 21.24 pounds of carbon emissions per gallon, unleaded 89 produces 19.52 pounds per gallon, unleaded 91 produces 19.51 pounds, unleaded 93 produces 19.88 pounds and bio diesel produces 5.02 pounds of carbon emissions per gallon.

You can purchase one-time carbon offsets for boat rentals or renting a sailboat, these are similar to other transportation offsets. The offset allows you to simply erase the CO2 emissions generated by paying to have a carbon sink created.

Manually Calculate Your Boat’s Carbon Footprint

For accuracy, you can figure up your boat’s CO2 emissions by a simple formula. Just multiply the number of gallons of gas you used for a specific time period, like a week. If you used 5 gallons of Marine diesel, that’s 5 x 21.24 pounds=106.2 pounds of CO2 you generated. So how many trees to offset a boat voyage?… It will depend on how many gallons of fuel were used. You can use the same formula if you know the emissions for the type of fuel you use in your car, or simply calculate your car’s carbon footprint here.

Full Sails Ahead! Buy Carbon Offsets for Boats!

A Native American proverb says, “We do not inherit the earth from our ancestors, we borrow it from our children.” Buying carbon offsets now will help preserve the planet for the future.

There are a variety of certified carbon offset programs but some are less reputable than others. Look for well-established certifications such as:

  • Green-e Certified Carbon Offsets. Green-e verifies the competency and fidelity of environmental products such as renewable resources and carbon offsets so you don’t have to. This is a well-established, trustworthy certifying body. Certifying bodies are comparable to licensing boards – they don’t provide any consumer services themselves, but they verify the quality of services being provided by those they certify.
  • Carbon offsets from the Gold Standard Marketplace: Gold Standard is another well-established certification body.
  • 8 Billion Trees provide reforestry carbon offsets for your boat, meaning that the emissions you produce are erased by new trees being planted in the Amazon and other countries around the world. But these sorts of offsets do more. They also protect existing forests and carry out wildlife rehabilitation and protection projects, partnering with a number of like-minded organizations.

As in any industry, there are inevitably bad actors and there are carbon offsetting pros and cons. Before purchasing your carbon offset, be sure you aren’t being scammed. You can check that our by simply doing an internet search of the name of the offset provider with the word “scam.”

Extras: Eco-friendly Boating Tips

After you buy your offsets, there are some other things that you can do to help lower your boat’s emissions.

  1. Check the tides and winds: Motoring against the tide or into strong winds requires more engine power – and thus more fuel – than sailing with them at your back.
  2. Change your fuel type: Biodiesel is much more environmentally friendly than diesel.

So grab your gear and hit the water… your boat offsets ensure that you’re protecting the environment, not having fun at its expense.