sailed a 46 ft steel boat that they built. To get the alternator speed up, the pulley on the prop shaft turned a second shaft which in turn drove the alternator via a second belt.

They circumnavigated the same time I did (1993-1998). I remember that he replaced the cutlass bearing a lot more frequently than I did. Actually, my original cutlass bearing lasted 16 years. I don't really know how often he replaced it but he always carried a supply of them and did it at least a couple of times when I saw the boat hauled out. I do not remember if he had a strut or a shaft log mounted cutlass bearing.

Also, if I were going to do a prop shaft driven alternator I would use a PSS to reduce friction and wear. I have a PSS now and like it.