Confusing earth wiring
When buying Vida, our surveyor included concerns about the earth.
We knew that the engine was "earthed" by a jump lead to the stern tube (and the jump lead was very rusty).
I've just found these wires connected to the anode that is bolted through the hull.

Quite a collection! We have green/yellow, back, blue and red!
Hardly surprising that the earth wasn't working!
#Oops