As an ex South African and Engineer
, the word "Vesconite" is a well known brand. I have not found one cruising friend of other nationalities that has heard about it.
Vesconite manufacture rudder
and shaft bearings to order, and they have worldwide distribution. The product is superb, long lasting and easy to machine. I have no ties to them, I just want to make my fellow boaters aware of them.
Entry to Design-a-bush calculators
This is a link to their bearing calculator, they also carry stock of well known boats spare parts
Best go and have a poke around their web site.