Unless, of course, it is intended to run it into the ground and strip as much profit from the carcass as can be managed:
“A planned system of inspection and maintenance has been shown in some circumstances to result in lifetime costs of about one sixth of the cost of neglecting the damage and replacing the structure when required to do so.”
PF Weber Structural Surveys of Oil Tankers. The Institute of Marine Engineers
The cost of installation of a protective coating is approx 10% or renewal of the plating concerned assuming a plate thickness of 12mm.
Inspection,Repair and Maintenance of Ship Structures Piero Caridis