Terms of use

Indicative tools, verified supply

The Prop Builder, calculators, charts and selectors on this site produce indicative outputs from the information you enter and from aggregated historical fitment records. They are decision aids, not specifications. No propeller, coupling or brake is supplied on tool output alone: every order is preceded by an engineering review, and we may decline to supply where we believe the product will not perform — see the Performance Promise.

Fitment data

Boat, engine and fitment information published on this site is aggregated from historical installation records, provided in good faith to help owners research. Production boats vary between years, markets and refits; data may contain transcription artefacts from decades of records. Always confirm against your actual vessel — that confirmation is exactly the service we provide.

Performance figures

Published performance figures (RPM reductions, fuel savings, drag and speed effects) are typical or maximum figures drawn from named independent tests and documented owner results, with assumptions stated where they appear. Individual results depend on the vessel, its condition and how it is used.

Intellectual property

Site content, illustrations, data compilations and tools are © 2026 Goaty's Marine and Bruntons Propellers Ltd. Autoprop, Varifold, Eco*Star, SigmaDrive and Autolock are trademarks of Bruntons Propellers Ltd, used with authorisation.

Consumer law

Nothing in these terms excludes rights you hold under the Australian Consumer Law. Where legislation permits limitation of liability for services, liability is limited to re-supply of the relevant service.