Electric harbour manoeuvres do not necessarily mean you have to remove the diesel engine from the boat. The Vetus Hybrid Set, model M2HSET, adds an electric motor to two M-Line engines. According to the manufacturer, the system is suitable for retrofitting compatible systems and for new builds.
The concept is aimed at boat owners who wish to retain their existing propulsion system and sail without running the diesel engine whilst casting off, mooring or on short, slow stretches. The internal combustion engine remains responsible for longer journeys and when higher power is required. The kit is not intended to replace the engine’s full propulsion power.
2.1 kilowatts for manoeuvring and slow travel
Vetus uses a liquid-cooled permanent magnet motor with an operating voltage of 24 volts. The manufacturer specifies a maximum electrical power output of 2.1 kilowatts and a maximum torque of 17 newton-metres. The connection to the propeller shaft is provided by a V-ribbed belt and a specially adapted pulley.
The performance figures show what this addition is designed for: according to Vetus, the M2.13 delivers 8.8 kilowatts or 12 PS, whilst the M2.18 delivers 11.8 kilowatts or 16 PS. In theoretical terms, the electric motor achieves just under a quarter of the rated power of the smaller diesel engine and just under a fifth of the rated power of the larger one.
When running on electric power, the vehicle moves slowly. Anyone who needs more power or has a longer journey ahead of them should switch to diesel mode. It is not possible to estimate the electric range based on engine power alone.
Technical specifications of the M2HSET
| Characteristic | Manufacturer's specifications |
| Compatible diesel engines | Vetus M2.13 and M2.18 |
| Electric motor | Permanent magnet motor, liquid-cooled |
| Operating voltage | 24 V |
| Maximum electrical output power | 2.1 kW |
| Maximum torque | 17 Nm |
| Maximum engine speed | 1,600 rpm |
| Charging current in diesel mode | up to 30 A |
| Connection to the propeller shaft | V-ribbed belt |
The position of the belt drive is crucial to its operation: it is located on the output side of the reversing gearbox. This allows the electric motor to drive the propeller shaft whilst the diesel engine is disengaged, without causing the internal combustion engine to rotate as well.
When running on diesel, the electric motor can operate in reverse as a generator. In this case, the rotating propeller shaft drives the electric motor via the belt. Vetus states that this generates a charging current of up to 30 amperes. At a nominal voltage of 24 volts, this corresponds to 720 watts.
This setup is not suitable as a power generator whilst at anchor: when the propeller shaft is stationary, there is no drive to power the generator. Allowing the diesel engine to idle is therefore not sufficient to recharge the batteries via the hybrid system. The charging function is a supplement whilst the diesel engine is running; it is not a substitute for a high-performance charging system.
Those who wish, above all, to improve the on-board power supply may opt for a different approach by fitting an additional alternator. This is driven directly by the diesel engine and does not rely on a rotating propeller shaft. Whether such a solution is suitable for a particular two-cylinder engine depends, amongst other things, on power requirements, installation space and the availability of a belt drive.
Retrofitting is only possible for compatible systems
In suitable installations, it should be possible to continue using the existing engine mounts and propeller shaft. Compared with a complete propulsion system replacement, this limits the scope of the conversion. However, the M2HSET is not a universal solution for any boat diesel engine. Vetus specifically mentions the two two-cylinder models, the M2.13 and M2.18.
To test your own system, Vetus is presenting at the M2HSET product page technical data and the accompanying installation instructions are available.
The first prototypes were on display at boot Düsseldorf in January 2026. No details are yet available regarding a price or a specific delivery date for Germany.
Book recommendation
Electric mobility on the water explains the technical principles behind electric boat propulsion systems. The book covers fully electric systems, hybrid solutions and fuel cells. Case studies on the conversion of motorboats and sailing boats complement the fundamental principles. Guidance on installation, operation and maintenance, as well as cost-effectiveness calculations, help readers to assess the effort involved in a conversion and to understand the differences between the various propulsion concepts.
Would you fit your motorboat with an electric drive for quiet manoeuvres in harbour and keep the diesel engine for longer journeys?
Hauke Schmidt
Test & Technology editor