Questions to ask any propeller supplier (including us)

Propellers are sold in two ways: from a chart in a catalogue, or from engineering. The difference is invisible on a website and very visible a season later. These six questions expose it in one phone call — ask them of anyone, including us.

1. "Will you refuse to sell me the wrong propeller?"

The only acceptable answer is an unhesitating yes, with examples. A supplier who has never turned an order away is a supplier who sells charts. Bruntons' record on this goes back decades, and the Performance Promise puts it in writing.

2. "What data do you size from — and will you show me the calculation?"

Correct sizing needs rated power, max RPM, gearbox ratio, shaft and clearance — then verification. If the answer is 'boat length', hang up politely. Our sizing explainer shows exactly what happens to each number, and the recommendation email restates the calculation.

3. "How is reverse thrust achieved, and has it been measured?"

Reverse is where cheap designs hide. Ask what the blade presents astern and whether stopping distance has been measured — the Autoprop's 7-second crash stop from 6 knots is published, alongside the 9.5–13 seconds of the alternatives.

4. "What's replaceable when it wears?"

A propeller with unobtainable internals is a consumable priced like an asset. Every wearing part of an Autoprop is replaceable, and older props can be factory re-pitched, rebalanced and bearing-upgraded rather than binned.

5. "Who services it in Australia, and where?"

A physical answer beats a shipping label: our answer is Shed 6, Queenscliff Harbour — strip-down, re-balance, bearing upgrades, with national shipping both ways. Ask any supplier for their equivalent address.

6. "What happens if performance disappoints?"

Listen for process, not promises: what gets measured, who reviews it, what the remedy path is. Our answer is written down in plain words — engineer review of the numbers, sea-trial comparison against prediction, and we make it right.

You'll notice none of these questions mentions price. That's deliberate: the cheapest propeller that's wrong is the most expensive thing you can bolt to a shaft.