ISO/TS 23099:2026

Large yachts — A methodologic framework to assess large yachts (30m+) on their environmental performance and credentials

Scope

This document specifies a methodology to calculate the environmental impact of operational energy use for large yachts and enables the comparative assessment of a yacht's environmental performance against a defined baseline fleet. The method established herein is robust and based on the best available data, with transparency and comparability across various yacht types and technical characteristics. This document explicitly addresses operational energy consumption during the yacht's use phase, emphasizing the efficiency of onboard systems benchmarked against the found average operational profile and the environmental emissions coming from this energy, both upstream and downstream. It excludes behavioural variables arising from individual yacht operation patterns. Additionally, the production and maintenance materials and processes (upstream impacts), as well as yacht end-of-life considerations (part of downstream impacts), are outside the scope of this document.
The operational profile specified in this document assumes that the yacht is professionally crewed year-round and capable of independent transoceanic voyages.
NOTE            For motor yachts, this operational assumption generally aligns with IMO MARPOL requirements, which apply to ships exceeding 400 GT that must be surveyed and certified for MARPOL compliance. Sailing yachts typically exhibit lower GT for equivalent length; however, their cruising behaviours align closely with motor yachts of comparable length.