The presence of even immature barnacles or tubeworms on the propeller causes a severe loss in propulsion efficiency. The technical solution on this problem is removing all calcium deposits and any basal plates with propeller polishing. Propeller polishing should be carried out to maintain the propeller surface roughness at or near-equal to Rubert scale A.
In service, regular underwater cleaning and reconditioning of the surface of a propeller is done with a small rotating disk that can easily conform to the complex shapes of the blades without gouging the surface. This tool removes all fouling and produces a very fine surface scratch pattern in the range of 1 to 2 μm. This is similar to what would be expected of a newly manufactured blade surface. Any large nicks or damage, especially to the leading edges or tips, should also be repaired and smoothed out.