The SEA Index is the result of a technical formula which calculates an environmental ratio from data across a range of criteria. Set against benchmarks and the average ratios of the superyacht fleet, the SEA Index assessment reveals if any given superyacht stands above or below the new baseline. If the relative environmental performance is truly excellent, it is awarded five stars, the highest rating. The number of stars decreases for yachts with a lower relative efficiency performance. Superyachts can then carry the SEA flag and be recognised for their environmental performance.

The SEA Index is a collaborative effort which has involved key industry players, from shipyards and operators to yacht owners who agreed to share their data to help establish the benchmarks. Of note, this is considered a work in progress as more data is compiled.

The index was created to provide an objective assessment, taking into account the specific use of superyachts. It primarily focuses on the levels of CO2 emissions while in operation. Instead of actually measuring emissions, it uses benchmark data to assess how yachts entering the index calculation process perform against the average.

General Information

Main Engines


Propulsion System

CO2 & Fine Particles

Gross Tonnage

Total Power

Waste & Water

Energy Recovery