What is Propeller Cavitation?

What is Propeller Cavitation?

Cavitation is bubbles caused by excessive propeller speed or loading. The water vaporizes or boils due to the extreme reduction of pressure on the back of the propeller blade. Many propellers partially cavitate during normal operation, but excessive cavitation can result in physical damage to the boat propeller’s blade surface due to the collapse of microscopic bubbles on the blade.

Propeller cavitation can cause:

• pitting on the surface of propeller blades
• vibrations when running – just like having an unbalanced or pitch-damaged boat prop
• reduced bite
• reduced overall efficiency of your propeller

What can be done to prevent cavitation or repair the damage caused by cavitation?

There may be numerous causes of propeller cavitation such as:

• incorrect matching of propeller style to the boat application
• incorrect pitch
• too little clearance between the prop and the hull or skeg
• physical damage to the boat propeller or lower unit or bottom of vessel

If you are experiencing propeller cavitation, please seek professional advice and repair. We can repair your lower unit, as well as your propeller. You may need to be running a different propeller in style, diameter or pitch, and we can help there too!

Cavitation Notes:

• Propeller cavitation is not generally a problem on low-speed vessels with low RPMs.
• Propeller cavitation is often confused with ventilation, which we will address in another post.