This part of ISO 15589 specifies requirements and gives recommendations for the pre-installation surveys, design, materials, equipment, fabrication, installation, commissioning, operation, inspection and maintenance of cathodic protection (CP) systems for offshore pipelines for the petroleum, petrochemical and natural gas industries as defined in ISO 13623.This part of ISO 15589 is applicable to carbon steel, stainless steel and flexible pipelines in offshore service.This part of ISO 15589 is applicable to retrofits, modifications and repairs made to existing pipeline systems.This part of ISO 15589 is applicable to all types of seawater and seabed environments encountered in submerged conditions and on risers up to mean water level.