Electric propulsion is no longer merely an interesting alternative at the edge of the narrowboat market. It is becoming a serious consideration for boaters seeking quieter cruising, lower local emissions and greater independence from fossil fuels.
On 12 July 2025, we attended the second Electrika Boat Show—an event dedicated entirely to electric boating.
Electrika is considerably smaller than major events such as Crick or the Southampton International Boat Show, but that is also its strength. Rather than treating electric propulsion as one subject among hundreds, the entire show focuses upon the technologies, design decisions and practical realities involved.
For us, planning a future all-electric narrowboat for full-time living and continuous cruising, it offered an unusually concentrated opportunity to learn.
Why Electrika matters to us
Priscilla is intended to become much more than a holiday boat. She will be our home, our means of travelling and the foundation for much larger journeys around Britain—and potentially beyond.
We want her propulsion system to be:
- Quiet and responsive
- Suitable for prolonged continuous cruising
- Efficient at ordinary canal speeds
- Capable of coping with rivers and stronger currents
- Supported by substantial solar generation
- Reliable and repairable
- Properly integrated with the domestic electrical system
- Resilient when charging opportunities are limited
- Adaptable as technology develops
Electric propulsion appears capable of meeting many of those ambitions, but only if the complete boat is designed around it.
It is not enough to replace a diesel engine with an electric motor and add some batteries. Motor output, propeller design, hull characteristics, battery capacity, charging sources and cruising patterns must work together as one system.
Electrika gave us the opportunity to explore those relationships directly with the people designing, installing and using the technology.
More focused than a conventional boat show
At a general inland-waterways festival, electric systems may occupy only a small part of a much larger exhibition. Conversations compete with boats, engines, interiors, accessories, entertainment and countless other attractions.
Electrika felt different.
The specialist nature of the event meant that nearly every conversation related directly to questions we are already considering for Priscilla:
- How large should the propulsion motor be?
- How much battery capacity is genuinely useful?
- What range might be achievable in different conditions?
- How much energy can realistically be replaced by solar power?
- What happens during several overcast days?
- How should propulsion and domestic energy reserves interact?
- What provision is needed for rivers and emergency manoeuvring?
- How easily can individual components be repaired or replaced?
- How should the system be monitored without overwhelming the user?
The show was compact, but the concentration of relevant knowledge made it exceptionally worthwhile.
Learning from the seminars
The seminar programme was one of the strongest parts of the day.
Technical information about electric boats is readily available online, but specifications do not always explain how components behave as part of a complete installation. The seminars helped connect individual figures—kilowatts, torque, battery capacity and propeller dimensions—to the realities of moving a heavy narrowboat through the water.
Three subjects were particularly valuable.
Selecting the right motor
Motor sizing is more complicated than choosing the largest unit the budget and engine bay will accommodate.
An oversized motor may add cost, weight and electrical demand without providing a corresponding improvement during normal cruising. An undersized system could leave insufficient reserve for stopping, turning, flowing rivers, strong winds or emergency manoeuvres.
The correct specification should reflect:
- Boat length, displacement and underwater profile
- Propeller characteristics
- Ordinary cruising speed
- Canal, river and tidal-water use
- Expected current and wind conditions
- Desired manoeuvring reserve
- Battery voltage and discharge limits
- Controller capacity
- Cooling arrangements
- Maximum continuous and short-duration output
- Redundancy and emergency operation
The distinction between peak and continuous output is especially important. A system may advertise an impressive maximum figure but be unable to sustain it for prolonged periods without reaching thermal or battery limitations.
For Priscilla, normal canal cruising may require comparatively modest power. Our concern is ensuring that the system also retains sufficient capability for the more demanding waters we hope to explore.
That does not automatically mean selecting the largest available motor. It means designing and testing the complete propulsion system against realistic operating scenarios.
Understanding torque
Electric motors produce torque differently from conventional diesel engines.
The immediate response can provide excellent low-speed control, while the absence of idling and gear changes can make cruising remarkably smooth. However, torque figures considered alone can be misleading.
The useful force ultimately delivered depends upon:
- Motor speed
- Reduction ratio, where fitted
- Propeller diameter and pitch
- Controller settings
- Battery voltage under load
- Current limits
- Motor and controller temperature
- Shaft-line efficiency
- Hull resistance
- Water depth and conditions
A high quoted torque figure does not guarantee that a boat will perform well if the propeller and drivetrain are poorly matched.
The seminars reinforced that propulsion must be considered from battery to propeller—not as a series of unrelated purchases.
Why propeller sizing matters
Propeller design emerged as one of the most technically interesting subjects of the day.
A propeller converts the motor’s rotational output into thrust. Its diameter, pitch, blade area and operating speed influence acceleration, stopping performance, efficiency, noise and energy consumption.
A poorly matched propeller could:
- Prevent the motor reaching its intended operating range
- Draw excessive current
- Waste stored energy
- Reduce cruising range
- Produce inadequate thrust
- Overload components
- Increase vibration or noise
- Cause cavitation
- Provide disappointing stopping performance
Electric propulsion can allow a larger, slower-turning propeller to operate efficiently, but a narrowboat’s stern shape, draught, aperture and rudder arrangement impose physical limits.
Propeller selection should therefore be undertaken using the characteristics of the completed hull, drivetrain and motor. It should not be treated as a standard component chosen solely from the boat’s length.
Priscilla’s builder, propulsion supplier and naval or marine designer will need to agree the relevant calculations rather than leaving each party responsible only for its own component.
Batteries are only part of the answer
Much attention in electric boating naturally falls upon battery capacity.
A larger battery bank can provide greater endurance, but it also introduces:
- Additional cost
- Greater weight
- More occupied space
- Longer charging times
- Cooling or temperature-management requirements
- Higher fault energy
- Structural and fire-safety considerations
- Eventual replacement costs
Capacity should be expressed as more than a headline kilowatt-hour figure. We need to understand how much energy is safely usable, what reserve must be retained and how performance changes with temperature, age and high electrical loads.
The battery also needs to support more than propulsion. Priscilla’s energy system may need to supply:
- Cooking
- Hot water
- Refrigeration
- Heating and ventilation
- Lighting
- Laundry
- Pumps
- Communications equipment
- Computing and video editing
- Safety and monitoring systems
- Battery and technical-space conditioning
The challenge is not simply to install enough storage for an average summer day. The design must remain workable during cold weather, heavy domestic consumption, limited solar generation and more demanding cruising.
Charging must match the way we cruise
Electric propulsion is often discussed in terms of range, but the rate and reliability of energy replacement may be more important.
Potential charging sources could include:
- Roof-mounted solar panels
- Shore power
- Dedicated charging points
- Propulsion regeneration, where conditions make it useful
- A portable or installed emergency charging arrangement
- Future charging infrastructure
- A range extender, if the final resilience assessment requires one
Solar generation is central to our ambition, but expectations must remain realistic.
A narrowboat roof offers a useful but finite area. Panels may be affected by shade, bridges, trees, roof equipment, orientation, dirt and seasonal changes. Summer output may support considerable cruising, while several grey winter days could produce only a fraction of the same energy.
Energy modelling must therefore examine complete journeys rather than a single optimistic day. We need to understand how far we can travel, how much power we can recover and what choices become necessary when generation is poor.
Designing for full-time living
A demonstration boat at a show and a full-time home have very different demands.
Continuous cruising requires a system that remains dependable across changing seasons, waterways and moorings. We may be away from shore power for extended periods and unable to choose an ideal charging location every evening.
The design must consider:
- Several consecutive cruising days
- Long stationary periods
- Shaded moorings
- Winter solar performance
- River passages requiring sustained power
- Unplanned delays
- High domestic energy use
- Battery degradation over time
- Failure of a charger, controller or solar circuit
- Access to technical support away from the builder
- Safe operation if monitoring or automation fails
Comfort should not depend upon ideal weather or a permanent electrical connection.
For that reason, Priscilla’s energy system will require clear operating priorities. Propulsion, steering-related equipment, pumps, lighting, communications and essential safety systems must be protected from less important domestic loads.
Monitoring without unnecessary complexity
Electric boats can generate an enormous amount of operational information.
Useful monitoring may include:
- Battery state of charge
- Voltage and current
- Individual charging sources
- Solar generation
- Propulsion power
- Domestic consumption
- Motor and controller temperatures
- Battery temperature
- Remaining energy reserve
- Estimated endurance
- Shore-power limits
- System warnings and faults
Good monitoring should help us make informed decisions. It should not create false confidence through an overly precise range prediction or require specialist knowledge to interpret every journey.
We would like Priscilla’s system to present simple answers to practical questions:
- Is there enough energy for the planned cruise?
- How much reserve will remain?
- Is solar generation meeting today’s consumption?
- Which domestic loads are consuming the most power?
- Is any component approaching a temperature or current limit?
- What should we do if part of the system fails?
Detailed engineering data should remain available for diagnosis, but everyday operation must be clear and intuitive.
Safety and installation quality
Electric propulsion removes some familiar risks associated with diesel engines, but it introduces others that require equally careful management.
A substantial battery bank and high-power electrical system demand:
- Correctly rated cabling and connections
- Suitable fuses and protective devices
- Safe isolation
- Appropriate battery management
- Temperature monitoring
- Ventilation or cooling where required
- Physical protection from water and impact
- Clearly documented emergency procedures
- Appropriate fire detection and response
- Accessible components
- Competent installation and commissioning
- Compliance with the applicable marine standards and regulations
The location of equipment will also influence weight distribution, cable length, cooling and maintenance access.
No major component should become unreachable once the interior has been completed. Priscilla must be designed so that batteries, inverters, controllers and other equipment can eventually be removed and replaced without dismantling the boat around them.
Quiet cruising
Technical efficiency is only part of the appeal.
An electric narrowboat can move with very little mechanical noise, allowing the sounds of water, wildlife and the surrounding landscape to become more noticeable. Conversation at the stern becomes easier, and there is no need to run a diesel engine simply to keep the boat moving.
That quieter experience aligns strongly with what we want Priscilla to represent: a slower, more attentive and less intrusive way of travelling.
Electric propulsion will not make the boat silent. The propeller, water flow, pumps, cooling systems and drivetrain can all create noise. Poor installation could also transmit vibration through the steel structure.
Motor mounts, shaft alignment, propeller selection, cooling equipment and acoustic treatment must therefore form part of the design if we are to achieve the quiet cruising experience we imagine.
Questions we still need to answer
Electrika gave us greater clarity, but it also helped identify the questions requiring further work.
Before committing to Priscilla’s propulsion system, we will need to establish:
- The completed boat’s expected displacement
- Required continuous and peak propulsion power
- Performance on canals, rivers and stronger currents
- Propeller and reduction-gear specification
- Battery chemistry, capacity and usable reserve
- Realistic summer and winter energy budgets
- Available solar-panel area and expected output
- Shore-charging requirements
- Domestic and propulsion load priorities
- Cooling arrangements
- Fire detection and emergency isolation
- Redundancy for essential functions
- Replacement access
- Component warranties and technical support
- Expected service life and future replacement cost
- The implications of battery degradation
- Compliance and certification responsibilities
- Performance following the failure of a major component
These decisions must be supported by calculations, not simply by attractive equipment specifications or claims based upon a different type of boat.
Small show, significant value
Electrika may not offer the scale, spectacle or variety of the larger events in the waterways calendar. That was never its purpose.
Its value comes from concentration.
In a single day, we were able to listen to specialist discussions, examine electric-propulsion technology and speak with people who understand the practical interaction between motors, batteries, propellers, charging systems and hull design.
We left with:
- A clearer understanding of propulsion-system sizing
- Greater appreciation of the importance of propeller matching
- More realistic expectations of battery capacity and charging
- New questions about resilience and component replacement
- A stronger sense of how the electrical and mechanical systems must be integrated
- Greater confidence that electric propulsion can support our ambitions when properly designed
Another step towards Priscilla
Electrika did not provide us with a ready-made specification—and that is probably its most useful contribution.
The show demonstrated that there is no single electric-propulsion package suitable for every narrowboat. The right system depends upon the hull, cruising pattern, domestic energy demand, available charging and the conditions in which the boat must operate.
For Priscilla, the objective is not merely to claim that she is electric. It is to create a genuinely capable cruising boat: quiet on the canal, confident on rivers, comfortable as a home and resilient when conditions are less than ideal.
Electrika 2025 brought us another step closer to understanding what that will require.
It may have been a small show, but for the future of Priscilla, it delivered some very big insights.