When it was launched nearly thirty years ago the designers of the Autoprop could not possibly have realised how important their unique design was to become. Thousands of cruising yachtsmen around the world sail faster and motor further and more economically using Autoprops.

With this history and its unique abilities it is not surprising that a new version of the Autoprop called the Autoprop Eco*Star has been developed to propel the rapidly growing number of hybrid and purely electrically driven craft, both motor and sail, which are being launched around the world. Its development has been the work of a formidable team of expert naval architects, engineers and scientists from Bruntons, sister company Stone Marine Propulsion, and the world renowned Insean Research institute in Italy who provided invaluable assistance in evaluating and testing the propellers characteristics, mathematical modelling and optimisation.

The ability of the props to
push the boat forward 1 knot
faster than previously is very
significant, and they also
create a lot less cavitation in
higher seas – a big problem
with the old props.”

Oliver Stapleton
13m Aluminium Catamaran
Solomon Electric Drive






Bruntons Propellers Autoprop Feathered



7 Diameters 380mm to 510mm or 15” to 20”
7 Shaft diameters 20mm to 35mm or 7/8” to 11/2”

H6E, H9E, H62E
7 Diameters 470mm to 900mm or 19” to 35”
7 Shaft diameters 35mm to 75mm or 11/2” to 3”


Benefits of the

Autoprop Eco*Star 

It’s already acknowledged that Autoprops are highly efficient because of their ability to auto pitch depending on engine speed and weather and sea conditions; an ability that provides optimum thrust at all times. But with purely solar or with hybrid power the list of advantages provided by the new Autoprop Eco*Star Propeller is further extended


  • Electric motors, unlike diesels, provide a constant torque from zero to maximum rpm. Only the Autoprop Eco*Star Propeller, using its auto pitching ability, can match its own efficiency curve with that of the electric motor. The result, a considerable improvement in the economy deliveries available compared with other propellers. Put simply, more boat speed but using much less energy.

  • On sailing yachts, when speed is not an issue but increasing battery energy is, the Autoprop Eco*Star Propeller can be allowed to turn in the vessels wake and the drive motor automatically becomes a generator recharging the batteries. Up to 1Kw of power can be regenerated in this way.

  • Displacement motor vessels of many types which are powered by diesel, hybrid or purely electric propulsion systems can also greatly benefit from fitting an Autoprop Eco*Star. The fixed pitch propeller fitted to most of these crafts will only be operating at its most efficient at or near maximum revs. Autoprop Eco*Star maintains exactly the right pitch whatever the engine revolutions ensuring the propeller produces significantly more thrust at lower propeller shaft speeds. The result; higher speeds at lower revs and better fuel efficiency

  • All the original Autoprop benefits are still available with the Autoprop Eco*Star Propeller. Backing down is much more efficient thanks to the propeller blades being the same optimum shape in astern as they are ahead.

  • Drag when sailing with the Autoprop Eco*Star Propeller’s blades feathered is reduced by up to 85%, providing speed increases of up to one knot.

  • For existing vessels the Autoprop Eco*Star Propeller is ‘retrofitable’. It comes already assembled to fit on an existing shaft or saildrive leg. It is silent in operation and optimises its pitch fully automatically. In short it provides the most environmentally responsible and efficient propulsion for any vessel powered by hybrid or solar systems.

Two very different craft, the same propellers, Autoprop Eco*Stars

For much more information about both craft and the significant improvement’s that fitting Autoprop Eco*Stars gave them just click the images

Zig Zag 3.jpg

Having decided to remove the diesel engine on his yacht and fit an electric one the owner of the Forna 41 Zigzag 3, Wim Clinkspoor, was confronted with a considerable reduction in propulsive power....read the full story


The ‘Energy Observer’ is a remarkable and highly advanced vessel which is totally energy self-sufficient and releases no greenhouse gases or fine particle emissions..click here for the full story

Ecostar Brochure Cover.png


The Autoprop Eco*Star brochure describes in some detail the unique benefits that you will obtain after you have fitted one to your vessel.

If, between the brochure and this website, you find yourself still with unanswered questions, please do not hesitate to contact us using any of the methods on the contact page.

Bruntons Propellers Logo B

PHONE US ON +44 (0) 1255 420005

UK office available weekdays 9:00 – 18:00