I have one of the "fish on a wire" type anodes in addition to the prop shaft zincs. It has a copper clip on the other end which allows me to connect it to my back stay. My back stay is bonded to my engine, all other stays, and all thru hulls. I also have a galvanic isloator installed for when I am on shore power. For two years I have hung the fish over the side when at dock. The first year I did not have the galvanic isolator and all I noticed is some white scale forming on it. This past year it actually had growth on it. I do not think that it really did anything since the currents had to travel through stainless rigging and down a suspect wire. I think that these "fish" anodes are not very effective, but they do offer peace of mind.