This standard provides a methodology to assess large yachts (30+ meters) on their environmental credentials and allows for comparison among the fleet as well as providing ratings. It includes a list of formulas to assess the various components that constitute the environmental impact of large yachts. The scope is limited to the operational efficiency of a large yacht, but could continuously be expanded until a yachts impact of the entire life cycle is assessable. The user scope of this proposal will be the yachting industry and all different parties involved, like yacht builders, yacht owners, brokers, research institutes and universities. The geographical scope of this ISO standard may be used globally.