NEXT GEN Marine

Decarbonising Smaller Vessels - Call for Evidence

22.04.2025

The new UK Maritime Decarbonisation Strategy includes a commitment to introduce emission reduction measures for vessels below 400 gross tonnage (GT).

The Department for Transport (DfT) are seeking evidence about smaller vessels in targeted sectors that could ‘move quickly’ where there are clear or advanced technological pathways for decarbonisation.

Evidence will also be relevant in targeted subsectors, recognising that some subsectors will be able to decarbonise more quickly than others.

A Call for Evidence (CfE) consultation period will run until 25 July 2025. A summary of responses, including the next steps, will be published within 3 months.

Through stakeholder engagement and evidence from projects funded through the government’s UK Shipping Office for Reducing Emissions (UK SHORE) programme, the DfT have considered the following 3 factors to assess clear and unclear pathways.

Vessel operations

The nature of a vessel’s operational activities impacts the ease with which it can reduce its emissions. For example, vessels that operate close to shore may be able to reduce their emissions more easily as there is more frequent access to refuelling and/or charging infrastructure. 

Vessel design

Larger, slower vessels may be able to reduce their emissions more easily for a given operational cycle, as energy needs are proportionally less than smaller, faster vessels. Larger, slower vessels are also more flexible in terms of carrying capacity, space and volume on board to fit batteries, alternative fuel tanks and propulsion systems.

Existing Case Studies

There are examples of zero, or near zero, emission propulsion systems already in use, or being trialled. The DfT have assessed projects from a variety of subsectors and used the data gathered. Through the application of these 3 factors, the DfT have identified small vessels that have a clear route to decarbonisation. These are vessels that have:

• Short duty cycles
• Regular opportunity to recharge
• Space on board for sufficient battery or hydrogen storage

Particular attention has been paid to cases where a representative technology demonstrator is present. This includes:

• Offshore wind operations and maintenance vessels
• Inland waterways vessels
  
• Recreational craft – excludes personal watercraft
• Ferries – only includes ferries travelling between UK ports
• Aquaculture vessels – servicing the aquaculture sector
  
• Port service vessels – vessels that support the operations of a port

The subsectors identified as currently having an unclear pathway to reducing emissions include but are not limited to:

• Oil and gas operations and maintenance vessels
• Deep sea tugs
• Pilot boats
• Pipe layer/cable layer vessels
• Research vessels
• Salvage vessels
• Lightships
• Fishing vessels

Background

The UK became the first major economy in the world to set a legally binding target to reach net zero emissions by 2050, under the Climate Change Act. This requires the UK government to set legally binding carbon budgets, which determine the maximum amount of GHGs that can be emitted in the UK over a 5-year period. Achieving this requires a reduction in GHG emissions across all sectors of the economy and across all modes of transport. Decarbonisation measures can also deliver other positive environmental impacts, particularly in reducing air pollution.

See DfT Call for Evidence - Decarbonising Smaller Vessels

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