Originally Posted by Hightower
When cruising down Portsmouth harbour this afternoon, punching the tide, when I tried to go above 5 Knots the prop cavitated and lost drive. It's been OK all day blasting around the Solent at 30+ Knots. Turned to go with the tide and all was OK again! No gear crunching was heard, but there was a mass of microscopic bubbles in the water behind the transom when this appeared to happen. Sea was flat calm with very little wind. I've had something similar happen in a rough following Sea but not in the calm!
Has this happened to anyone else and what do you think were causing the bubbles in the water?
I think that the with the tide / against the tide might be a bit of a red herring. However, microscopic bubbles sounds like either cavitation or ventilation. Could the propeller have been fouled by some weed or a plastic bag which has since come off?
Propeller bush starting to let go - lots of revs but little drive once you get above a certain RPM?
Have you since tried full power and if so does it all now work as it should?
I ought to make an effort to get up to the Churchillian - is it this week?