a. Yes, definitely yes. Read our webpage Voyaging with 2Extreme for a good reason to do so. On a voyage from New Zealand to Fiji, Henry McAlarnie lost steering due to a severed rudder post. voyagingwith2extreme.htm Be sure to check for electrical continuity between the zinc and the rudderpost, if you attach the zinc to the rudder shoe. On the other hand, if you have a self steerer, you can hang the zinc externally from the steerer with a wire to the rudder post inside the boat. Lester