Propeller Basics - Diameter

Diameter

Diameter is the width of the circle that the prop would make when rotating. The diameter can vary by up to 1/2" with no discernable change in performance.

Caution: Before increasing the diameter of your prop, make sure there will be enough clearance between the blades and cavitation plate or anode on your engine.

Diameter is the first number listed on boat propeller dimensions.

Diameter is the width of the circle that the propeller would make when rotating.
Propeller Help Guide
P is for Propeller Propeller Basics
How To Choose A Prop
Diameter Pitch
Cupping Rake
Ventilation Cavitation

We tell you everything you need to know about props from cupping to ventilation.

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If you want to modify your boat's performance, consider the above before making your selection.

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Effect of pitch on RPM
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For safety and efficient performance, it is critical that your engine operates within the RPM range recommended by the manufacturer.