When we first put Wind Horse in the water, we did not fit hull zincs. We were relying on the prop zincs, and zincs hung from the rail at anchor for galvanic protection. The zincs were being eaten too fast so we decided to pay the drag penalty (small) and weld plates with threaded holes to which we could bolt large zincs to the keel and near the props (four in total).

We've been watching the behavior of the prop zincs to see how much longer they last. The photo below was taken of the zincs recently removed, after ten months of work. The removal process resulted in quite a bit of the damage.