Mike. I am glad you have asked this question as I am going through a similar thought process myself. I believe that the recommendation for Atalantas is to bond all of the submarine metalwork – seacocks, keel steelwork, engine, shaft and prop -together with wires and connect to an anode. (Although I cannot at the moment find the article I think I have read that describes this – if anyone know will let me know I will improve the website indexing).
Helene, as I bought her, has a soft anode but no bonding between the various items. And she chewed up the new shaft anode last year in less than a full season. So I am looking at applying the internal bonding and perhaps adding a hull mounted anode in addition to the shaft anode.
One additional question. The talk of stray currents from other boats on shore power. I had previously thought this is only a problem if your boat is also connected to shore power, when you should fit a galvanic isolator. If you are ‘off-the-grid’ you should not be affected? I wonder if my experience last year proves this assumption to be false. I spent about 6 weeks in a marina, not connected to shore power, but where there were rumours from other Atalanta owners that the pontoons I was on were known for electrolysis issues due to their proximity to a large steel lightship-clubhouse.
It would be great to hear others’ opinions on what bonding / protection should be applied to an Atalanta and also whether shore power connections impact the situation. Nick