Guys remember:
Zinc for salt water
Aluminum for salt or fresh water
Magnesium for fresh water

I have a few boats that I service that are low 1990's that I replace the aluminum anodes every few years that the outdrives and etc still look real good. Yes, original outdrives. These sit at docks in fresh water by themselves from early June thru late September. No shore power.

Some other boats in area where owner refuses to have anodes replaced (silly isn't it) the outdrives look like total schit. Same people will sand down and redo paint on outdrives every few years. I show them the older boats outdrives I referenced above and they still just shrug there shoulders.

Crazy !

Most people are just their own enemies.