I was thinking some small electrodes, that run down the fin, to give them an uncomfortable tingle when they try to contact it. That way, it would still maintain

I was thinking some small electrodes, that run down the fin, to give them an uncomfortable tingle when they try to contact it. That way, it would still maintain a direct cause->effect relation from the fin, and not directly related to a human. There are electric shark deterrent systems, but I don't think they're very good at speed, where the electrodes could be applied to the fin, using marine-readied conductive tape, or just thin wires at the leading/trailing edges.