Electrolysis monitoring?

I forget where I came across a story about a very large and expensive alloy yacht in which the hull was completely destroyed in a rather small amount of time. The cause was believed to have been some kind of conducting wire that had been dumped into the water nearby the yachts moorage.

Are there any systems available that could have alerted the crew to the corrosion?

 

Checking for galvanic corrosion is very simple, all that is required is a reference electrode and a cheap multimeter. It is something you do when you spot corrosion or paint blisters that weren't there before. It is also done when a new hull is fitted with anodes to make sure they are in contact with the hull and have sufficient surface area for the size of the hull, exposed metal area and the conductivity of the water the ship is moored in.

I am not familiar with that particular story, but it is not impossible that such a thing really happened. It may also be a fairytale originating from a source with a distinct interest in cathodic protection.