1 Scope 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 systems for offshore pipelines for the petroleum and natural gas industries as defined in ISO 13623. This part of ISO 15589 is applicable to carbon and stainless steel 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. NOTE Special conditions sometimes exist where cathodic protection is ineffective or only partially effective. Such conditions can include elevated temperatures, disbonded coatings, thermal insulating coatings, shielding, bacterial attack, and unusual contaminants in the electrolyte.