How Is a Boat’s Electrical System Grounded When It Is Out of the Water but Still on Shore Power?


Hi Jeff, I am a new boat owner and have a question that I hope you can answer on your YouTube channel.  If a boat is grounded in the water by the prop shaft/keel, how is it grounded on stands out of the water? I ran my engine to winterize it on the hard with the AC shore power still connected and on for my charger. Did I do any damage to my electrical system, specifically my alternator, if my boat isn't grounded? Is there a safety risk with the boat out of the water connected to shore power? - Pete


In this case, we would recommend confirming the grounding tie between your A/C grounding system and the D/C negative, this completes the grounding system for both A/C and D/C when connected to shore power. The tie to ground would then be through the A/C ground shore power inlet.