To begin this topic it is important to give a brief explanation of what cavitation is.

The cavitation phenomenon occurs when a propeller turns its blades and expels the water backwards, leaving a gap that is immediately filled by new liquid molecules.

The blades create such a depression (decrease in pressure or gap) on their front face that water boils at room temperature; the bubbles that then come out of the propeller are not air, but strictly water steam.

These bubbles move quickly backwards, until they find an area of higher pressure where they will become water again, imploding (the opposite of exploding) against the propeller blades themselves and tearing out (eroding), in each impact, a microscopic metal particle.

The most important effects caused are:

• Blockage of the liquid passage sections. As in ducts, in the channels between blades, the presence of bubbles decreases the useful passage section, giving rise to flow accelerations that reduce the overall efficiency of the propeller.
• Erosion of the surface of the blades. This is the surface deterioration and roughness generated by the bombardment of the bubbles on said surface (the so-called orange skin appears on the propeller).
• Wavy trailing edge in the presence of vortex cavitation at the tip of the blades.
• Noise and high frequency vibrations generated by the hatching of bubbles on the surface of the blades. The noise can become annoying while the vibrations can lead to structural damage (fatigue) of the propeller sections.