Developed by Yacht Club de Monaco under the aegis of the collective ‘Monaco, Capital of Advanced Yachting’ initiative, the SEA Index® is now recognised for its rigorous CO₂ emissions assessment methodology applied to yacht design.

With more than 130 yachts over 24 meters already certified, it has become an international benchmark for assessing environmental performance in the yachting sector.

This latest development is another milestone in the evolution of the SEA Index®, as its scientific methodology is now accessible to a much larger segment of the pleasure boat fleet worldwide.

In collaboration with Lloyd's Register (LR), the SEA Index® has developed new benchmark models tailored to:

  • Displacement, semi-displacement, and planing monohulls;
  • Production catamarans up to 35 meters in length.

The new models are based on an extensive dataset aligned with international maritime energy efficiency principles. It means boats can be compared against benchmarks specific to their design characteristics and operational profiles, ensuring assessments are consistent, comparable and based on objective criteria.

Broadening the SEA Index® scope allows many more stakeholders to access this independent certification framework for assessing CO₂ emissions.

In particular:

  • Shipyards and boat builders can use the tool to integrate environmental considerations from the early design phases;
  • Owners and buyers have access to clear, reliable and comparable information on CO2 emissions, regardless of boat size;
  • Ports, marinas and finance stakeholders can apply harmonised environmental criteria across the whole recreational boating ecosystem.

By expanding its scope beyond superyachts, the SEA Index® is supporting a more inclusive and structured transition for the whole recreational boating sector.

Bernard d'Alessandri, President of the SEA Index® and YCM General Secretary, said: “This development marks a significant milestone for the SEA Index® and the nautical industry as a whole. By applying our methodology to recreational boats from 10 metres, including production boats and catamarans, we are making environmental assessment more inclusive and accessible. Our goal is to help establish a credible, transparent framework for everyone to support improvements in the environmental performance of the recreational fleet worldwide.”

Dr Chris Craddock, Global Lead – Marine Asset and Operational Performance at Lloyd's Register, said: “The SEA Index® methodology has been refined to better reflect the diverse operational profiles of production yachts and superyachts, and the significant differences in hydrodynamic performance associated with different hull shapes and speed regimes.

“By benchmarking vessels against specific reference curves, established using rigorous methodologies aligned with IMO decarbonisation measures, the SEA Index® offers a fair, transparent, and internationally consistent framework for assessing environmental performance across the entire yachting sector.”

With this expansion, the SEA Index® is consolidating its position as a benchmark for environmental assessment by extending its scope beyond superyachts to cover the whole yacht market. By including smaller boats and production models, the SEA Index® is helping boost availability of comparable verified data on the sector’s CO2 emissions.