Fresh water anodes?

[boatmike]

Just doing a final refit before heading down the French canals to the Med. Replacing all anodes with new zinc ones, but it dawned on me I shall be in fresh water a lot of the time so should I get a magnesium one to dangle in the water when moored or is the experience of the folorumites that it's not really a problem?

 

[macd]

The alternative to a dangly magnesium anode is to fit aluminium anodes, which work in both fresh and seawater. Bear in mind, too, that if you stick with fixed zinc anodes but spend much time in brackish water at either end of the trip, they will generate a surface coating which renders them inert. This needn't be a problem, particularly heading to the warm waters of the Med, if you're able to dive in and give them a scrub.
(My home port used to be brackish, so I've used ally anodes: they're fine, at least on a GRP boat.)