In monitoring an impressed current cathodic hull protection system, it is important to insure that the propeller screw receive the same cathodic protection as the hull. What should be checked for?

Correct Answer: Option C — Insure adequate grounding carbon brush pressure on the rotating shaft and check brushes for wear.

Propeller assemblies form dissimilar metal galvanic cells with the hull. To ensure complete cathodic protection, dedicated shaft grounding brushes must maintain positive low-resistance carbon brush contact against the rotating shaft, allowing protective current to flow across the water film.