Anywhere on anything that has an electrical connection to the saildrive. However I've gotta say do some more research because you can overprotect aluminium by having too much zinc. I am not an expert in this but 30 years ago I owned a 54ft aluminium ketch which had signs of corrosion so I had to find a solution. Worse corrosion occurs when you hook up to shore power and you effectively connect any thing that is earthed on your boat with the earths on other vessels that are hook up to shore power. In this situation if your boat has earthed aluminum parts and the other boat is steel or has earthed steel, the aluminum in your boat protects the steel on all the earthed boats in the marina. You effectively have an electrical connection between aluminum and steel, which now serve as an anode and cathode sitting in an electrolyte, salt water. The salinity of the water has an effect an also the number of steel boats or marina that may have stray currents due to faulty electrical connections.

The solution for an aluminum boat was an isolation transformer or an electrical current passing through a platinum electrode on the bottom of the boat, this current protected the boat. There were other methods using zinc anodes but they were messy due to the fact that the situation changed with the environment that the boat sat in also the qualtity of the zinc was questionable.

At the time Quicksilver had a similar system using a current through an electrode attached to an aluminum leg in the water. I would research that.

Happy Days

Frank Aquilina

On 21 Feb 2018, at 07:18, Marc Duffy marcone35@... [lagooncatowners] <lagooncatowners@...> wrote:

I've been advised to hang a high content magnesium zinc from each of my sail drives due to the salt/brackish water condition in my canal.?

Does anyone know where the attach points are on the sail drives please??

My advisor suggests internal to the engine compartment.

thank you