Chef ... only occurs under power. We have had this girl for about 18 months now and the problem has only popped up after this haulout. She's fin and skeg btw. See below.
Mark .... nothing mechanical was touched. Haulout was for bottom clean, antifoul and anodes. I checked all anodes before she went back in and they were all good and tight.
Now ... further information .... six months or so back we managed to get our signals mixed when dropping mooring and ran over the dinghy painter which was tied to the mooring buoy. Buoy and dinghy met up at the prop shaft. Luckily I realised what was about to happen and had her in neutral by the time the line reached the shaft but there was still some turn in the prop when the line arrived. Problem was resolved by rotating the shaft from inside the boat in the reverse direction until line cleared. Dinghy was somewhat the worst for wear as was the buoy but that was six months back and there has been no problem with shaft or prop in that time. We are out and about pretty much every weekend other than for family occasions. This includes right through (our admittedly very mild, albeit not very windy) winter when we do a lot of motoring.