Re: what is cavitation??
JB is correct. I've never had a prop actually cavitate, but I have had plenty "ventilate." I am real familiar with cavitation in the centrifigal pumps in fire trucks. Sounds like the pump is full of gravel. "A Lesson-Cavitation <br />Cavitation is probably one of the most misunderstood and used words in boating. Here is a crash course in the basics. When a propeller breaks free in a sharp turn it is actually ventilating, not cavitating. The prop breaks the surface of the water and sucks air in and loosens the grip on the water. The plate above your prop is actually an anti-ventilation plate, not a cavitation plate.<br /><br /> Cavitation actually transpires when a fully submerged prop creates a low-pressure area on the backside of the blade. The prop is turning so fast that the hole it cuts in the water has not had a chance to fill. Low-pressure in this area allows the water to actually boil at the lower temperature and bubbles are formed that can create a feeling of an unbalanced prop. Those bubbles also eventually implode under the increasing water pressure and can actually eat away the paint and metal on the prop. This not only makes it look bad but can weaken the blades. Having a prop with too much cup, nicks or a sharpened leading edge caused by filing the surface in the blades, can increases the possibility of the condition. The next time you see a swath of removed paint form the blades of your propeller, this is likely what you are seeing."<br /><br />Sean Horsfall
