What metal anode type would I want to use for a boat that spends about 90-95% of its time in fresh water, and a few days a summer in salt? When I do go into salt, we go out and come back in through locks, so I always end up back in fresh water. Boat is used close to 300 hours a summer, but is stored on its trailer and not in the water. Every once in a while it will stay in the water over the weekend, but that happens maybe 3 or 4 times a summer for 2 nights max.
I assume zink anodes would be pointless for the amount of time I am in fresh, but is it better to go with magnesium or aluminum?