A propeller may not be changed with one of a different pitch unless stress evaluations are supplied and permission is granted by a Marine Surveyor.

When steel propellers are used, zinc anodes are to be fitted on the aftermost strut bearing housing and on the forward most section of the rudder assembly.

The exposed steel of the shaft is to be protected from the action of the water by filling all spaces between the cap, hub and shaft with a suitable material.

Ultrasonic examinations of the propeller may be performed in lieu of required dry-docking periods, provided certified copies are distributed to the proper regulatory bodies.