The interactions between CP and the fatigue and hydrogen embrittlement characteristics of alloys are explained. Sacrificial (or galvanic) anodes and impressed current systems are examined, followed by descriptions of successful and unsuccessful applications on petroleum installations, harbours, jetties, pipelines, windfarm foundations, ships and floating production storage and offloading vessels FPSOs. Retrofit CP systems for the life extension of assets, together with methods for applying CP internally in both static and flowing systems are evaluated. A critical review of the role of physical and computational modelling in CP design and evaluation addresses the more geometrically complex applications. Techniques for, and limitation of, CP surveying, inspection and monitoring are explained in the context of system management. This text is ideal for engineers, designers, manufacturers, equipment suppliers and operators of offshore CP systems.