What is an anode?

[Tranona]

Well thanks gang for info.
My boat is a Jeanneau Fantasia, 27 ft, lift keel, 1984.
Bought it of a chap who had it from new.
When anti fouling in spring, noticed prop shaft was fully coated with anti foul.
My guess is that it has never had anode fitted to shaft.
He had boat on a swing mooring, as i do also.
Have 2 wing prop (bronze coloured) with looks in very good shape to be honest.
Must admit will probably beach boat later and fit anode to prop shaft, as i deem it can do no harm to do so.
Many thank chaps...

If it has never had one save the few pennies to spend on something you do need!

 

[millbeach]

Just out of interest.
How much would a zinc anode cost for my prop shaft?

 

[Spyro]

Just out of interest.
How much would a zinc anode cost for my prop shaft?

£15 give or take a couple