My new boat is a sailing yacht and I will not be lifting the boat out and changing the anodes every time that I go on a cruise.

I hope that I will be out of the marina for more than 2 weeks every year so magnesium would seem to be a problem.

The boat will be on it's moorings for most of the time so Zinc seems to be a problem too.

Has anyone tried the aluminium based alternative?

If I use zinc and magnesium together (by dropping a magnesium anode over the side) won't the zinc and magnesium react?

It's a bit of a dilemma, can anybody else shed a light?