Rudder Stock corrosion and water leak

Do not bond the rudder stock, the rudder sits in synthetic bearings and the autopilot drive arm is on synthetic bushes so its not possible for the rudder to pick up stray current from the vessel. having the rudder isolated is the best way to protect it. It is however able to pick up stray current from the bonding wire if there is an issue with termination, leak in and around the boat from neighbours etc.

Bonding to the engine is not great idea as saildrive anode is designed only to protect the saildrive mass, not the engine, not the keel, not the rudder and many of older Hanse have all of these elements bonded together. All this will do is cause the saildrive anode to waste rapidly and once its gone the enxt inline will sacrifice. The saildrive anode is aluminium, the hull anode is zinc, means hull anode has holiday doing nothing while saildrive anode does all the work. Of most concern is cable that joins the DC neg bus bar and AC earth bus bar meaning anything bonded is also connected to earth of the pier for better or worse. Your anodes will waste away in matter of weeks/months. (see my detailed posts under my user name on removing the AC-DC connection).

I had communications with Jefa when i replaced my rudder and they confirmed they disagree with Hanse's approach to bonding the rudder and recommend its left isolated and correct antifouls used.