Recommended anode on prop shaft for fresh water?

Jan 22, 2008
99
Hunter 30_74-83 Rochester, New York (Lake Ontario)
Hello,

The options seem to be aluminium, magnesium, zinc, or a combination. There are claimed and obvious differences in effectiveness. I sail Lake Ontario and out of curiosity, what do sailors recommend for protection on prop shafts on our great lake?

Recommendations?

Thanks,
Bob