The International Organization for Standardization (ISO) has formally approved ISO/TS 23099, introducing for the first time a harmonised and science-based method to assess and compare the environmental performance of large yachts over 30 metres in length.
The Technical Specification builds on the outcomes of the Yacht Environmental Transparency Index (YETI), a joint industry project spearheaded by the Water Revolution Foundation. It was developed under ISO Technical Committee 8 (TC8), Subcommittee 12 (SC12) for large yachts and has been approved by national standardisation bodies representing major yacht-building nations, including Italy, the Netherlands, Germany, Turkey, Poland, the United Kingdom and the United States.
ISO/TS 23099 is also the first completed project of Working Group 6 (WG6) on Large Yachts Sustainability & Environment within TC8/SC12, highlighting the sector’s growing commitment to measurable, transparent and credible environmental responsibility.
Five years of industry collaboration
The Technical Specification is the result of a five-year joint effort involving leading shipyards, naval architects, technical experts, research institutes and classification societies. Its objective is to establish a robust and practical methodology to assess and compare the operational environmental performance of large yachts.
Unlike commercial shipping, the assessment is based on a yacht-specific operational profile: 10 per cent cruising, 34 per cent at anchor and 56 per cent in port. The outcome is expressed as a score against a reference line within different gross tonnage categories, enabling meaningful comparison across the fleet.
From CO2 equivalents to EcoPoints
In addition to translating multiple environmental indicators into CO2 equivalents, ISO/TS 23099 introduces EcoPoints, a more comprehensive metric commonly used in life cycle assessment. EcoPoints combine several environmental impact factors, including CO2 and NOx emissions, into a single indicator. This approach allows users not only to understand overall impact, but also to model improvement scenarios for both newbuild and refit projects.
A common language for the superyacht sector
By defining a consistent framework and assessment methodology, ISO/TS 23099 provides the superyacht industry with an internationally recognised reference. It supports informed decision-making in new construction and refit projects, facilitates continuous improvement and helps avoid fragmented or proprietary approaches.
According to the Superyacht Builders Association, the approval of the new ISO reference underlines shipyards’ proactive commitment to decarbonisation and enables further validation through practical application. At the same time, it may serve as a foundation for future yacht-specific emission provisions within the international regulatory framework.
With ISO/TS 23099, the sector takes a decisive step from voluntary sustainability ambitions towards a measurable and standardised environmental benchmark for large yachts.
