Monaco, JULY 8th 2026
SEA Index® is extending its environmental CO₂ assessment to pleasure boats from 10 metres, marking a significant step towards greater accessibility and transparency across the global boating market.
Originally developed for yachts above 24 metres, the SEA Index® has certified over 120 vessels and is recognised for its rigorous carbon emissions framework in yacht design. This expansion brings the same independent, science-based methodology to a much wider segment of the global fleet.
By including smaller pleasure boats, both monohulls and catamarans, the SEA Index® moves beyond the superyacht segment to reflect the reality of the industry: a diverse and largely unassessed fleet where environmental benchmarking has until now been limited.
Photo Credits ©Magnific.com – Aerial view of yachts and leisure vessels at anchor in crystal-clear waters.
Methodology Adapted for Smaller Boats and Multihulls
SEA Index®, in collaboration with Lloyd’s Register, has developed new reference models tailored for:
- Displacement, semi-displacement, and planing monohull boats
- Production catamarans up to 35 meters.
These models are based on extensive datasets and aligned with international maritime efficiency principles, ensuring fair and consistent assessments.
They enable environmental performance to be evaluated across a broader spectrum of pleasure boats, taking into account their diverse operating profiles and design characteristics.
A Step Towards Broader Accountability in Boating
This expansion represents an important milestone in the evolution of environmental transparency in leisure boating. For the first time, a rigorous and independent certification framework becomes available across a wide range of pleasure boats, including production vessels and multihulls.
It enables:
- Shipyards and manufacturers to integrate environmental performance from early design stages across larger production volumes
- Owners and buyers to access clear, comparable and trusted information, irrespective of vessel size
- Ports, marinas and financial stakeholders to apply consistent environmental benchmarks across their boating ecosystem
By extending beyond the superyacht segment, the SEA Index® supports a more inclusive and structured transition for the boating industry as a whole.
Leadership Perspectives
“This expansion marks an important evolution for the SEA Index® and for the boating industry at large. By extending the methodology to pleasure boats from 10 metres, including production vessels and catamarans, we are moving towards a more inclusive and accessible framework for environmental transparency. This is about ensuring that credible and consistent environmental assessment is not limited to a small segment of the fleet, but progressively becomes available across the full spectrum of boating.”
Bernard d’Alessandri, President, SEA Index®, Secretary General, Yacht Club de Monaco
“The SEA Index® methodology has been further refined to better reflect the diverse operating profiles of production yachts and superyachts, together with the significant differences in hydrodynamic performance associated with varying hull forms and speed regimes. By benchmarking vessels against dedicated reference lines derived from rigorous methodologies aligned with IMO decarbonisation measures, SEA Index® delivers a fair, transparent, and globally consistent framework for evaluating environmental performance across the yachting sector.”
Dr Chris Craddock, LR Global Lead for Marine Asset and Operational Performance
Strengthening Environmental Benchmarking Across Boating
With this expansion, the SEA Index® reinforces its role as a leading environmental assessment framework, extending its scope beyond superyachts to the broader pleasure boating market.
By integrating smaller vessels and production boats, the SEA Index® contributes to establishing a common, data-driven foundation for environmental transparency, supporting long-term progress across the global boating ecosystem.
About the SEA Index®
The SEA Index®, developed by the Yacht Club de Monaco, is an environmental performance assessment tool for boats, designed to measure and compare their impact using objective, transparent, and independently verified criteria.
It supports a growing international network of:
- Yacht owners and captains
- Marinas and ports, including 25 locations across the Mediterranean, Seychelles and St Barthélemy, and 87 marinas through the Japan Marina & Beach Association
- Maritime ecosystem stakeholders (banks, insurers, shipyards and technology providers)
The initiative aims to encourage continuous improvement through measurable data, contributing to a more structured and achievable transition of the boating sector.
Press Contact: info@sea-index.com
About Lloyd’s Register Advisory
Lloyd’s Register Advisory is a global professional services division within Lloyd’s Register, dedicated to helping clients navigate the complexities of the maritime and energy sectors. With a team of over 250 experts spanning technical and commercial disciplines, LR Advisory delivers strategic guidance across decarbonisation, digitalisation, regulatory adoption, and operational performance.
Our services support a diverse client base, including shipowners, ship yards, OEMs, charterers, financiers, alternative fuel suppliers, port authorities, and governments, offering tailored solutions that drive safety, sustainability, and competitive advantage. From asset performance and risk management to project delivery and ESG strategy, LR Advisory combines deep engineering and commercial expertise with advanced digital tools to unlock value and future-proof operations.
