This document 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. Hardware Subsea infrastructure used to aid in the gathering of hydrocarbons, excluding pipelines, flowlines, risers and jumpers are not included in ISO 15589 as they covered by different industry standards. This document is applicable to carbon steel, stainless steel and flexible metallic pipelines in offshore service. This document is applicable to retrofits, modifications and repairs made to existing pipeline systems. This document is applicable to all types of seawater and seabed environments encountered in submerged conditions and on risers up to mean water level.