This part of EN ISO 19901 provides requirements and guidance for the planning and engineering of marine operations, encompassing the analysis and design of the components, systems, equipment and procedures required to perform marine operations, as well as the methods or procedures developed to carry them out safely. This Standard is applicable to marine operations for offshore installations This International Standard may also be applicable to subsequent modifications to existing structures e.g. installation of additional topsides modules.This Standard is not applicable to the following marine operations: construction activities onshore, where there is no exposure to the marine environment; drilling, process and petrochemical activities.