While impact is measured through CO2 emission levels, it is not the only criteria. One of the important aspects is that the index takes into account the CO2 per gross ton, which is representative of the volume of the vessel’s enclosed space – a measure of the utility of the vessel without influence of the space usage.

Efficiency is key

The online calculator gives applicants an initial rating of the yacht’s CO2 polluting emissions.  Upon review of adequate data documentation, the next step, is for each yacht applicant  to apply to become a member of the Superyacht Eco Association and be remitted with their exclusive SEA Index certificate. This certificate is independantly verified by Lloyd’s Register, the internationally-renowned independant certification company.

The rating metric of the SEA Index is based on the approach taken by the UN’s International Maritime Organisation, plus specific customisations for application to superyachts. The initial benchmarks were generated from data provided by 130 yachts, ranging from 40-140 meters in size, with every data point of the assessment collected and validated by the SEA. Phase II of the SEA Index has included data from over 300 yachts. The approach taken is to calculate a representative CO2 emission rate at sea and a representative CO2 emission rate when at anchor/berth and weight them by a nominal operating profile.

SEA Index Ratings

Once data is registered, the SEA experts evaluate the results and attribute a rating from 0 to 5 stars to the applicant yacht. The percentage rating bands are defined to divide the yachts into a rating class, with an equal distance of 25% between the rating bands. The star rating system will evolve with the index over time.