Boat Propellor Anatomy - The Basics

parts of a boat propeller - the basics

learn it - test it - check it


  • Outer Hub = Exterior hub
  • Inner Hub = Hub inside (sacrificial centre)
  • Splines / Ribs =  Connections between inner & outer hub
  • Diffuser Ring = Flare ring on the back 
  • Diameter = Distance across the circle swept by prop blade tips
  • Pitch = Distance prop 'theoretically' travels in one revolution 
  • Rake = Angle blades are set relative to outer hub
  • Hole Shot = From dead stop (in the hole) to up on the plane


  • Blade Tip = furthest bit from the hub
  • Blade Back = Blade side facing forward
  • Blade Face = Blade side facing backwards
  • Blade Root = Attachment point to hub
  • Leading Edge = Forward part of the blade
  • Cupping = Curl in the blade towards the trailing edge

test yourself:

Parts of a Prop Test.pdf
Adobe Acrobat Document 367.6 KB

check yourself:

Parts of a Prop Test Answers.pdf
Adobe Acrobat Document 371.4 KB

additional Resources:

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