What is ISO 19901-1?

ISO 19901-1 provides requirements for determining and using meteorological and oceanographic, or metocean, conditions in the design, construction and operation of offshore structures.

It covers both the identification of relevant environmental conditions and the characterization of the metocean parameters needed to describe them. These include extreme and abnormal conditions, long-term statistical distributions and normal environmental conditions expected during the service life of an offshore structure.

The standard supports the determination of environmental actions for new and existing structures, site-specific assessment of mobile offshore units, construction and decommissioning activities, and operational planning. It is intended to be applied with engineering judgement, particularly where available environmental data are limited or uncertain.

Why is ISO 19901-1 important?

Offshore structures are exposed to environmental forces that can vary significantly by location and may include rare but severe combinations of wind, waves and currents. In many regions, historical measurements are limited, making the reliable estimation of extreme and abnormal conditions a critical engineering challenge.

ISO 19901-1 provides a consistent framework for establishing the metocean conditions used in structural design and offshore operations. This helps organizations account for uncertainty, define suitable design and operating criteria, and support appropriate reliability across different offshore structure types and locations.

By linking metocean assessment with the wider ISO offshore structures framework, the standard also supports more consistent decisions across design, assessment, installation, operation and decommissioning.

Benefits

• Provides a consistent framework for determining metocean conditions used in offshore design, construction and operations
• Supports the assessment of extreme, abnormal and frequently occurring environmental conditions
• Helps account for uncertainty when historical wind, wave and current data are limited
• Supports design and reassessment of fixed and mobile offshore structures across different locations
• Helps define limiting environmental conditions and weather windows for installation, operation and decommissioning activities
• Promotes consistent integration of metocean information with structural reliability and offshore engineering decisions

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