Back in August I noticed that the cavitation plate anode was missing. I assumed that when I fitted it I couldnt have tightened it up properly. Oh well, off to Darthaven for a replacement, and our local friendly engineer in Torquay fitted it on her berth. yesterday was a beautiful day so we took a trip over to Brixham for lunch. Got back in and the replacement is missing! When we bought her the surveyor and my mate picked up a vibration on the boat which was eventually put down to the props and Ancasta fitted 2 new sets. I took the same mate out today and he could feel a slight vibration on the starboard side where the anode is missing. Cant see any visible damage on the props so I am thinking we may have hit something in the water as some point and knocked one out of balance. I am going to have them taken off and balanced - dont want to replace them, they are less than three years old. I f I have been running with a damaged prop since August am I likely to have caused any damage to the sterndrive? Anybody else had a similar issue??