Propelling Our Future: Pathways to decarbonization for recreational boating

By Jeff Wasil
Sr. Director, Environmental Health & Safety, NMMA

Our love for boating is fundamentally reliant on a healthy and sustainable marine environment, and we must take care of that resource to ensure the experiences boating provides can be enjoyed for generations to come. Which is why proactively advocating for a science-based, real-world approach to the recreational marine industry’s efforts to further decarbonize its global footprint is a strategic priority for NMMA. Conveying the right path forward is important because recreational boating’s market demands, energy needs, safety concerns and use cases are unique.

Last year at METSTRADE, NMMA joined ICOMIA to release a breakthrough lifecycle assessment (LCA) study outlining the portfolio of technologies best positioned to further propel our industry toward decarbonization. The global research, which looked at marine propulsion in boats under 24 meters in length, revealed that due to the unique on-water environment for recreational boating, and the varied interests of boaters and types of on-water experiences, a variety of propulsion solutions must be considered to reduce carbon emissions.

ICOMIA’s independent, peer-reviewed research report, titled Pathways to Propulsion Decarbonisation for the Recreational Marine Industry, provides guidance to global governments and boating stakeholders as they work together to shape investments in technology and policy. The study shows that good marine public policy must take a technology-agnostic approach, support innovation, and not focus on any one type of energy or propulsion system.

Our industry has a great story to tell. Recreational boats account for less than 0.1% of all global greenhouse gas (GHG) emissions, specifically 0.7% of transportation carbon dioxide (CO2) emissions in the U.S. and 0.4% of transportation CO2 emissions in Europe. For context, 46% of emissions are generated by powering homes and industry, and 14% of emissions are generated by global transportation. We produce durable products—many with a life of 30 to 50 years. Marine engine emissions have decreased by more than 90% over the last 20 years while fuel efficiency increased by more than 40%.

Unlike cars, which are relied on to get from point A to B, recreational boats are used for leisure and vary significantly in not only how, but how often, they are used (e.g., many gasoline-powered recreational boats are operated an average of 35 to 48 hours per year). The research also looked at the impact on cost of ownership based on propulsion technology, and compared to boats on the water today, increases in cost of ownership ranging from 5% to 250% are expected until alternatives achieve market scale.

With a variety of boat types and experiences offered, the research showed there is no universal, “one-size-fits-all” approach to decarbonize recreational boats. As a result, in addition to leveraging current internal combustion and fossil fuel-powered boats, we must consider a portfolio of emerging technologies, including:

Sustainable marine fuels, such as renewable drop-in fuels, are expected to be the most suitable source of energy to decarbonize recreational boats by 2035 – by as much as 90% – without compromising distance or performance. With 30 million recreational boats in use worldwide, with an average lifecycle of 30 to 50 years, there is tremendous potential for increased decarbonization of the existing fleet with immediate, widespread adoption of sustainable marine fuels.

Hydrogen is an emerging technology and another potential source for reducing carbon emissions from boats if the production process can be optimized. Hydrogen, if produced via electrolysis with zero fossil fuel electricity, can reduce carbon emissions for certain boat categories.

Electric propulsion is part of the strategy to decarbonize, however, until there is a battery density breakthrough, it is not suitable for all boat types and use cases. This study considered both battery lifetime in years and recharging cycles as battery performance is expected to degrade over time regardless of utilization. This could impact watercraft with a long lifespan but not frequently used as it may require several battery replacements during its lifetime.

Hybrid boats using both electric and internal combustion engines powered by liquid fuels offer the potential for reducing carbon emissions from boats in certain cases (e.g., boats used for longer periods of time and for greater distances). Hybrid technology provides the most potential for emissions reductions for boats that are used for rentals and other high-use environments.

Advanced hull design and efficiency improvements are also critical in reducing friction and power requirements from recreational boats and are paramount in our ability to further improve emissions.

In addition to these propulsion system technologies, there is much opportunity to further reduce the carbon intensity of boat manufacturing through use of different materials, production processes, and manufacturing facility energy requirements.

This research offers guidance on the focus for the future innovations we can begin exploring today to create a better boating experience that reduces our overall environmental footprint. It also aligns us in collectively advocating for a global policy agenda that includes advancing a technology neutral decarbonization approach for marine environments, acceleration in development and distribution of sustainable marine fuels, establishing marine electric technology standards and consumer safety protocols and more.

To learn more about the research, visit PropellingOurFuture.com.