Thanks for those comments which make me wonder if this is just a prop grease issue??? Let me explain ...
Firstly I should say that this boat has never been cruised before Lauren and I set off 1.75 years ago. Up until before I owned it the previous owner had done just 600 hrs on the engine and half that on the generator in 10 years of ownership, plus employed an Amel technician bi-weekly for 10 years to care for her. Based on this I doubt that I could have any U Drive issues or major prop wear as we have been very careful owners too.
I had originally intended to do my normal 2 year haul-out in Cape Town but we became pinned down by bad weather in Durban unable to get any 33hr+ weather windows to sail down to East London on this notoriously dangerous coastline. Because of this, and with time for the Cape Town haul-out dwindling, I haul out in Durban instead, and did the normal prop wearing bearing replacement, bottom paint, plus lifted the waterline stripe.
On turning the prop blades out the water they didn't seem as smooth as normal, and on top of this, in my rush to get back into the water when a possible good weather window was forming, I did not re-grease the prop. That could possibly be the source of my issues, and rather foolish as I have always been so painstakingly careful to follow each and every step to the letter!! In fact I have never greased this prop as I simply sent it back to Bruntons last time to do the bearing change and grease in their factory.
In order to make a run directly for Cape Town (900nm approx) I sailed out of Durban early into the end of the previous SW front and therefore had to motor sail for a day before we picked up good wind and current. Over the next 3 days we shot down the coast breaking all our past records with 3 consecutive 200nm days with our best ever 24hrs clocking up 225nm!! Great sailing indeed and we ran as hard as we could direct for Cape Town right out at sea with pole out and all sails up until rounding Cape Agulus (most southern tip of Africa) where we had to turn NW into un-predicted 30kts head wind and 4+ knot adverse current making for hard motoring to maintain just 3 kts forward motion. When I say hard, that means max 2000 RPM on the Yanmar 75 (very seldom would I ever run the motor above this).
It was at this time that I noticed more prop noise and that there was a slight resultant vibration on the top of the UDrive unit only, not on the main engine side at all. We immediately reduced to usual 1400 - 1600 max revs and crawled into Cape Town to ensure no damage could be done. At those revs there was absolutely no vibration visable at all.
I will drop you a personal email sometime regarding the Indian Ocean crossing as it has been awesome and I hghly recommend it, but course you can also follow our videos on "Sailing Island Pearl" https://www.youtube.com/channel/UCmvAE1BtOM7J8orw237BDgQ?view_as=subscriber
, but in summary from far east Indonesia through Singapore, Malaysia, Thailand, Maldives, Chagos, Rodrigues, Mauritius, Runion, Madagascar and now South Africa we have spent 1.75 years in the Indian Ocean and absolutely loved every minute of it. We have faced 50+ knots, 6m+ seas and this boat has been unbelievable as it never ever felt unsafe or out of control to either myself or any crew on board. These are outstanding boats indeed and I learn to respect Captain Amel more and more every day that I sail and live aboard the Amel Super Maramu.
SV Island Pearl II, SM#332.
Royal Cape Yacht Club, Cape Town