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Pathways to Propulsion Decarbonization for the Recreational Marine Industry

research by Syntia

As leisure boaters increasingly want to make informed choices about the most sustainable way of enjoying their boating experiences.

In research commissioned by International Council of Marine Industry Associations (ICOMIA), CEO Joe Lynch and Jeff Wasil, Sr. Director Compliance NMMA, presents a condensed overview on the recreational boating, providing vital insights and signpost where more information is available.

A significant decline in the greenhouse gas emissions we emit is crucial at the moment, and we’re not on track to achieve those targets. Therefore, it’s essential that we all work urgently to make the required changes.

What’s interesting, though, is that the leisure marine sector constitutes only a tiny part of the overall global emissions. We’ve calculated that it makes less than 0.1% of the total global greenhouse gas emissions and 0.4% of Transportation GHG emissions in Europe.

One option would be to dismiss ourselves as the small players, focusing on larger sources like ships, lorries, and industrial processes. However, as an industry, we don’t think that way. We want to embrace the responsibility we have and ensure that we pass on our industry and its benefits to future generations.

Nevertheless, we do face a problem with perception. If you look around this show, most of the pictures depict boats burning fuel at high speeds. This image doesn’t help us. We spend a lot of time talking with governments, and it’s easy for them to target super yacht owners and those driving boats irresponsibly. Yet, we, as lovers of this industry, know that this is a far more realistic picture.

Who is it easy to target?

It’s the Super yacht owners. It’s the people driving their boats irresponsibly, fast making noise and pollution. But yet at the same time, we as lovers of this industry know that this is a far more realistic picture. We know that boating really does enrich people’s lives. We go on the water to have health benefits. We know that stress levels reduce.

Due to the paradox between the image of fast boats burning fuel and the reality, we realized there was an absence of data. How can we expect policymakers to make the right decisions without the right data? That’s why we commissioned a report from Ricardo, an international engineering consultancy.

Boat usage profiles

Options for traditional gasoline or diesel for internal combustion engines (ICE) exist, along with sustainable alternatives like hybrid electric, battery electric, and hydrogen systems. The analysis covered boats from small inflatable tenders to high-performance motor yachts, excluding super yachts for now.

We hope to cover super yachts in additional research. Making like-for-like comparisons is challenging, so we focused on the usage profile. Average lifespan, low utilization, and energy density played crucial roles in the boat life cycle analysis.

Now, many of you know that it’s hard to make like-for-like comparisons. The analysis had to consider usage profiles, lifespan, and energy density. We optimized the model to find the best possible solution for usability, safety, and viability.

The hybrid technology on this boat is roughly the same, a little bit increase in overall CO2 emissions. If you move toward electrification on this particular boat, you get about 10% reduction in overall greenhouse gas emissions over the life cycle of the boat. But what’s really interesting here is if you look at the role sustainable marine fuels can play, specifically fuels in the ability to reduce CO2 emissions, you’ll see a 60% reduction in this boat and there is a reduction with hydrogen as well.

As we move to a displacement motorboat, with the baseline diesel fuel, hybrid, you have almost a doubling of the amount of carbon. Now keep in mind, this data was calculated to 2035. Again, because the energy intensity of the battery production is so high, especially with such a large battery required for this boat. If you’re not going to utilize that boat on a regular basis then you’re front loading an enormous amount of carbon into a vessel and the vessel is going to outlast the propulsion system batteries in this case. So that’s why you see such an increase again about a 40% reduction with sustainable marine fuels and an increase in hydrogen as well producing the hydrogen tanks.

The high pressure storage tanks again are very energy intensive. With sailing yachts auxiliary power the engine is going to run for about 24 hours with a per year so low utilization with a lifespan of about 45 years.

Recreational personal watercraft are operated about 35 hours a year, at high rental application can have a significant reduction in CO2 emissions using electrification. Drop in fuels still have a lot of potential for reducing CO2 in this application.


Length (m)


Power (kW)

Fuel (L)

Engine Hrs pa

Life (Y)

Inflatable Tender







Fishing Boat







Displacement Motorboat







High Performance Yacht







Sailing Yacht







Pontoon Boat














PWC (Hire)







Inland Waterway Vessel







Ricardo’s assessment

Ricardo’s assessment with nearly 600-page report covers propulsion types, life cycle greenhouse gas assessment, total cost of ownership, boat power system implications, and suitability ranking. There’s no one-size-fits-all solution for reducing carbon emissions from recreational boating. Factors like retirement rate, energy density, and usage patterns vary widely. However, new Ricardo report shows that making it easier to switch to cleaner transport enables economic growth.

As an industry, we have the advantage of not being boxed into a single technology. The diversity of products and propulsion systems allows us to address global climate change through various means tailored to different types of boats and their usage patterns.

Starting with a review of the decarbonization propulsion types and systems and then questioning- How would they fit the boat in terms of functionality? What’s the impact on range? What’s the impact on the weight of the boat? And then we did a full life cycle greenhouse gas assessment. We worked with three different independent agencies according to the IPCC guidelines as well as ISO guidelines for doing comprehensive life cycle analysis. We then looked into the total cost of ownership. How much is it going to cost to produce these boats with new technology?

What is it going to cost the consumer to buy these things as well as maintaining these boats and infrastructure, the boat power system. And finally, what is the impact on range, power, performance, usability of the boat all the way through the infrastructure implications.

Average utilisation

We’ve studied the average utilisation per year of all of the boats around the world and it is surprisingly low now. There are outliers. I’m sure there’s people in the audience who will say, hang on, I use my boat at least 300 hours a year. Well, congratulations, you’re very lucky. When we do these calculations on real world data-we also need to be real in the approach we take to trying to balance what’s the difference between running on a conventional, sustainable, sort of conventional diesel fuel to electrification.

And we had to go through a process called optimising the model. If we wanted to model a boat running purely on electric power and maintain the range that you get with diesel, it’s just simply not viable. The battery pack required would be too big, too heavy and the boat might flounder. So we had to do the analysis based on optimization. What would be the best possible solution to make the boat usable and safe and viable?

Following excerpt from the interview with Benetau group CEO Bruno Thivoyon about sustainable boating at Beneteau.

Reducing carbon footprint

Do you think consumers are doing enough, or do you think we need to start making changes, and they have to follow?

“It’s another good question because educating is probably the easiest solution. Last year we were saying that if you want to really have a short and significant impact, the number one priority is to reduce the speed. How do you educate to reduce the speed for everyone? First, knowing the speed synapse will help us understand the real speed and design the boat to the actual speed used. Second, show that there is an intermediate limit, which is the one the boat has designed for, and if you go above it, you consume more. It’s not meant for that. The variation is higher, the usage experience is worse. So, remind owners what the boat is designed for; it is extremely important.

Limit the speed, use the boat at the right speed and educate- not only through promotion or advertising but mainly when delivering the boat. It’s important to know how the boat was designed for the higher speed, and second, reduce it. Show that when you are over the limits, what if you have an electric power and you don’t raise it saying ‘I have enough energy to go to my home or to my work.’ But, this is not what is being followed on the traditional boats. It could be probably answered better by the police,- reducing the speed has to be promoted. We could all go sailing instead. I used to say that the first natural energy is the wind. So, that we came from that 140 years ago. We are 50%, almost 50%, of our size are side boat. So yes, use wind, that’s a good point.

If we all went to electric today, I think we’d be able to use our boat probably twice a year. So there are major issues as an industry we face in regards to that.”

What are your thoughts on electric, and do you think it is an interim measure before innovation catches up when it comes to fuel cell, hydrogen fuel cell?

“I think many solutions will come, and it will be a panel of solutions that will bring exactly back in the automotive. But it will take much more time than what we think at the moment. The automotive launched it, and it will not be the only solution. Today we are much less electric than what automotive thought 10 or 15 years ago.

We had much more hybrid, but hybrid helps in growing in these intermediate solutions. I agree an electric boat is a good transition to learn consuming less not on the propulsion side but on board on the hotel mode, and with an alternative fuels.”

Teak decking for the boat

In regards to teak decking, what are your thoughts on moving away from it and using alternatives?

“From the teak, we have moved away today completely and shifted to a new iroko deck material, which we now call Iro-Deck. It took us a long time to switch from Teak to iroko. There are still some shipyards that are using alternative teaks. But from a customer experience, I think iroko is a good and even a better solution, because it’s a structurally good one.”

Do you think our boating will look like sustainable entertainment, that’s usage?

“I think boating is one thing, but we spend more time on the boat without sailing or without using it without propelling it. So, I think it’s important to work on both how long we spend time on the boat, which is not selling or not so sustainable entertainment boating industry.”

Great. Thank you for the insights. More information about the boat modelling and material design on their website: https://www.beneteau.com/interview/sustainable-boating-beneteau

Assumptions about recreational boats

Reducing CO2 emissions with automotive is not the same as recreational boating.

#1 is the retirement rate of recreational boats. We are selling boats at a retirement rate of about 2%, which means the average lifetime of a recreation boat is between 30 and 50 years. Very long time relative to automotive.

Number two is energy density. When you look at an electric car, for example, let’s say it’s got a 478 kilometer range. What a lot of folks don’t realize is if that electric vehicle is operating the way a recreational boat does, specifically clean recreational boat, it would only have about a 48 kilometer range. And that’s because it takes about 10 times the energy to move a boat through the water and that does to propelled cars.

#3, if I ask a question, what are the majority of cars doing in major cities around the globe right now? They’re being used. They’re stuck in traffic, constantly being used. If I ask the same question, what are the majority of recreational boats doing right now? Absolutely nothing. They’re sitting around in marinas and waiting.

Future model that technology accelerates

So the we talk about the importance of a life cycle analysis tool and I think that’s absolutely fundamental in our ability to understand if a certain technology and a certain use case is really going to reduce CO2 emissions. Because at the end of the day, that’s our goal. Our goal is not to implement XYZ technology. Our goal is to reduce CO2 emissions through whatever means possible. So relying on on comprehensive life cycle analysis models are really important. We’re in the process of developing that.

Certainly, Ricardo has done a tremendous job with their model, but I think a lot of boat builders, engine manufacturers and the rest need access to these tools to understand how to do that. So there is a bit of a learning curve, but it’s a great opportunity moving forward as we kind of harmonize our industry behind this life cycle analysis model to start using it in a more meaningful way moving forward.

Having that one trusted approach is really important because we are a global industry and we don’t want people in one country using one methodology that isn’t respected somewhere else. And that’s very much, it’s still in the early stages, but we’re quite excited about the plans on the horizon about developing the harmonised approach that will allow us to develop the tools that will allow everybody to make really informed day to driven decisions.

Next steps

This comprehensive report, developed with Ricardo, provides valuable insights for informed decision-making. The future plan for Iconia Group and its partners involve continued research, lobbying governments, and supporting emerging technologies. The goal is to drive supply by stimulating demand for sustainable options and operating boats responsibly to the environment.

An additional relevant evolution in retail is that consumers seek to  associate themselves to sustainable and socially conscious brands. Companies from all industries are now expected to integrate environmental and social values across their entire value chain.

Brands are also shortening their supply chains; bringing their manufacturing processes closer to home. This particular strategic change comes with several benefits such as more flexibility within the supply chain and economic advantages for local communities and improved environmental conditions.

With an aims to continue campaigns, utilizing the wealth of data to influence governments, promote sustainable options, and foster innovation in the boating industry. The collaboration between industry players and consumers is crucial for achieving a sustainable future.