Cavitation, which is often confused with ventilation, is a phenomenon of water vaporizing or boiling 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 propeller’s blade surface due to the collapse of microscopic bubbles on the blade.

There may be numerous causes of cavitation such as incorrect matching of propeller style  to the boats application, incorrect pitch, physical damage to the propeller, etc.

Be advised disturbances in the water flow forward of the propeller can result in blade damage which appears to be cavitation, but is actually due to non favorable water flow to the propeller.