The best propeller? Wrong question.
After six posts about fixed, folding, feathering and self-pitching propellers, here’s the most important point of the series: the propeller doesn’t work by itself. It’s part of a propulsion system, and choosing the right one takes more than deciding on two, three or four blades.
To size a propeller properly we need the engine’s maximum horsepower and rpm, the gearbox reduction ratio, the shaft or saildrive, and the boat itself: waterline length, displacement and the space available behind the hull. From those we work out diameter, pitch, hub and blade configuration.
One principle is especially useful. For the best efficiency we normally want the largest diameter the aperture and clearance will allow. A larger, slower-turning propeller is generally more efficient than a smaller, faster one, particularly on a displacement sailboat or catamaran. But the engine and gearbox have to be able to turn it, so even that rule isn’t applied in isolation.
Which is why I don’t much like the question “What’s the best sailboat propeller?” There isn’t one.
The better question is: what’s the best propeller for my boat, my engine and the way I sail?
Here’s the good news for the show. You don’t need to arrive with a folder of numbers. Tell me your engine make and model, and I’ll look up its power and rpm and check the propellers already fitted to boats like yours in the Bruntons installation records. Then tell me what you’d like to improve: less drag under sail, better reverse, less prop walk, lower cruising rpm, better fuel economy, easier motor-sailing, less noise.
In a few minutes you’ll have a sizing for each type that suits your boat, with show pricing, on a postcard to take home. Anything we can’t check on the dock, such as the gearbox ratio or shaft size, we confirm afterwards before anything is ordered.
Come and see us at the Annapolis Sailboat Show, Booth YB3, City Dock, October 15–18. Tell me your engine model and I’ll size your propeller while you’re there. You’ll walk away with your sizing and show pricing on a postcard. No numbers needed: just know your boat and how you use her.
Next: would you trust your propeller in Antarctica?
#AnnapolisBoatShow #SailboatPropellers #CruisingSailboat #MarineEngineering
