In this paper, we will deal with theis sue of ship building and corrosion, which is the main factor in this problem. How to plan maintenance more properly, more efficiently and more effectively, and the types and ways of applying certain resources to certain parts of the ship's construction. The work is conceived in several units: In first section, we will explain the ship's construction and all the elements of the ship in order to understand how certain parts of the ship are importantand how they affect the longitudinal and transverse strength of the ship, and how important it is that their maintenance is planned and efficient to keep those elements functional In its sense. In these condpart we will describe and explain the types of corrosion and how they affect and what factors are needed in their emergence. In the third part, we will deal with the protection of the ship's construction in phases, with the application of coating protection, and we will specifically explain the cathodic protection. And in the final part we will be dealing with performance calculation and corrosion protection control,economy and maintenance cost. The accent is on protection and protection methods as well as the maintenance plan. Proper maintenance increases the percentage of ship and crew safety and prolongs the ship's usability.