Electrolysis?

[Weeb]

I pulled my boat the other day to wash it and add lateral thrusters and noticed what looks like electrolysis attaching to the metal on my pumps, ride plates and intake. I wet slip in a marina that has power. I leave the boat with the battery switches off and a battery charger plugged into the dock and it is a fresh water lake. The pictures are from after I washed it so it doesn’t look as bad as when I pulled it out. When I rub it it turns powdery and comes off. The anode doesn’t look like it’s being attacked that much. Could this be from power getting into the water from the marina? I have a multi meter I could use to test if you can, just not sure how to do it.
Sorry forgot the pictures lol.

 

[haknslash]

Yes most likely from power around your marina. BTW I can't see any pics.

Whatever you do don't jump into that water https://www.electricshockdrowning.org/esd--faq.html