A couple of years ago, whilst the boat was out of the water for some work under the hull, I decided at the last minute it would be a good idea to fit a shaft anode. This was not only to protect the propeller but also to act as a failsafe should the shaft come adrift from the flange mounting it to the gearbox. In this instance the anode would prevent the shaft falling back and crashing into the rudder in reverse or even falling back enough to let water into the boat through the stern gland.

In a hurry, I managed to track down a zinc anode from Norfolk Marine in the knowledge I really needed an aluminium anode but considered it better than nothing.

The reality is that the zinc anode had no effect and showed almost no sign of erosion in two years submerged. This was even the case despite having cruised on the southern Broads.

I now have an aluminium 1 ¼" fitted, so it will be interesting to see if that is effective next time the boat comes out.