Every large yacht owner has, at some point in the last two years, been asked by a broker, surveyor, or well-meaning charter guest whether their vessel is "CII compliant." The honest answer for the overwhelming majority of superyachts is that the question doesn't apply — but the confusion is understandable, because IMO's decarbonization framework has moved fast, and the tonnage thresholds that exempt most yachts aren't widely explained in yachting media.
This guide sets out exactly what CII and EEXI require, why most superyachts fall outside their mandatory scope, what the voluntary Superyacht Carbon Intensity Indicator actually is, and where the binding IMO Net-Zero Framework stands as of 2026.
Source: IMO, EEXI and CII — Frequently Asked Questions (imo.org); IMO Net-Zero Framework FAQ (imo.org); MEPC.338(76); Lloyd's Register, Superyacht Carbon Intensity Indicator (lr.org); SuperyachtNews, 13 May 2025.
What CII and EEXI Actually Are
Both instruments were adopted under MARPOL Annex VI and entered into force on 1 November 2022, becoming mandatory from 1 January 2023. They address different things and apply to different ships.
EEXI (Energy Efficiency Existing Ship Index) is a one-time technical assessment — similar in concept to the design efficiency requirement applied to newbuilds (EEDI), but retrofitted onto the existing fleet. It calculates a ship's theoretical CO₂ emissions per unit of transport work based on engine power, ship type, and size, and compares it against a required baseline. EEXI applies to ships of 400 gross tonnage and above.
CII (Carbon Intensity Indicator) is an ongoing, annual operational rating — not a one-time design check, but a yearly measure of actual fuel consumption relative to distance sailed, adjusted for ship type and size. Ships receive an annual rating from A (best) to E (worst), and consistently poor ratings trigger a corrective action plan requirement. CII applies only to ships of 5,000 gross tonnage and above engaged in international voyages.
The gap between these two thresholds matters enormously for yachts. A vessel large enough to cross the 400 GT EEXI line is common among 70m+ superyachts. A vessel large enough to cross the 5,000 GT CII line is not — that tonnage is closer to a mid-sized cruise ship or cargo vessel than even the largest private superyachts currently in service.
Why Most Superyachts Fall Outside CII
This is the point most owners and captains get wrong, usually because CII gets discussed in yachting press without the tonnage qualifier attached.
The overwhelming majority of superyachts — across the entire under-30m to 70m+ range typically discussed in the yachting industry — sit well below 5,000 GT. Gross tonnage is a volumetric measure, not a length measure, and yacht hull forms are far less voluminous relative to their length than cargo or passenger ships. A 70m yacht with a luxurious, low-density interior layout can easily sit in the 1,500–2,500 GT range — nowhere near the 5,000 GT CII threshold.
This means: CII, as written today, does not directly apply to the vast majority of superyachts. No annual carbon intensity rating, no A–E grade, no corrective action plan requirement under CII specifically — because the tonnage gate excludes them.
EEXI is a closer call. Some very large yachts — particularly those over roughly 70–80m depending on hull form, volume, and internal layout — can cross the 400 GT line and fall under EEXI's mandatory one-time assessment. Owners of yachts in this size range should have their naval architect or classification society confirm GT against the 400 GT threshold specifically rather than assuming exemption by length alone.
Gross tonnage, not length overall, is the determining factor for both CII and EEXI. Two yachts of similar LOA can have meaningfully different GT depending on hull form, superstructure volume, and interior layout. Don't estimate your exposure from LOA — get the vessel's actual GT confirmed against both the 400 GT and 5,000 GT thresholds.
If Your Yacht Is Captured by EEXI: What Compliance Actually Involves
For the smaller number of large yachts that do cross the 400 GT EEXI line, it helps to know what the assessment actually requires, since it's a materially lighter process than the ongoing CII rating.
EEXI is a one-time technical calculation, not a recurring annual measurement. A naval architect or class society calculates the vessel's attained EEXI value based on installed engine power, hull characteristics, and ship type, then compares it against the required baseline for that vessel category. If the calculated value already meets the requirement — common on newer or efficiently designed yachts — no further action is needed beyond the paperwork.
If the vessel doesn't meet the baseline, owners generally have two practical paths: technical modifications to improve fuel efficiency (propeller upgrades, hull coating improvements, energy-saving devices), or engine power limitation (EPL), also referred to as shaft power limitation — a verified, often software- or hardware-enforced cap on maximum engine output that brings the calculated EEXI value into compliance without requiring a full re-engine. EPL is the more commonly chosen route industry-wide because it is significantly less costly than a propulsion system overhaul, though it does cap top-end performance.
Either route is verified and certified by the vessel's classification society as part of the existing survey framework — it does not introduce a separate, parallel compliance regime to manage.
CII's Reduction Targets — Relevant Even If You're Exempt
For the ships CII does apply to, the annual reduction targets under MEPC.338(76) are steep, measured against a 2019 baseline:
| Year | Required reduction vs. 2019 baseline | |---|---| | 2023 | 5% | | 2024 | 7% | | 2025 | 9% | | 2026 | 11% |
These targets continue tightening through 2030 under the current regulatory trajectory. While most superyachts don't fall under CII's mandatory scope, this reduction curve matters as a reference point for two reasons: it signals the direction IMO's broader decarbonization framework is heading, and it forms the underlying logic for the voluntary superyacht-specific scheme covered below.
The Superyacht Carbon Intensity Indicator (SCII): Voluntary, Not Mandatory
Recognising that most superyachts sit outside CII's mandatory scope but face growing owner and charter market interest in demonstrable environmental performance, Lloyd's Register partnered with Blue ESG to develop the Superyacht Carbon Intensity Indicator (SCII) — a voluntary certification applying CII-equivalent carbon intensity logic to yachts over 400 GT.
Key points about SCII:
- It is not a regulatory requirement — no flag state or IMO instrument mandates it
- It applies the same underlying methodology as CII (fuel consumption relative to distance and ship size) to a size band that CII itself doesn't reach
- Owners and yards pursue it as an opt-in market signal — comparable in spirit to a green building certification, demonstrating verified performance rather than self-reported claims
- It positions vessels ahead of any future mandatory extension of carbon intensity rules to smaller tonnage bands, should that occur
For owners weighing whether to pursue SCII certification, the calculation is closer to a reputational and charter-market positioning decision than a compliance obligation — a genuinely different consideration than EEXI or ISM Code compliance, which are not optional where they apply.
The IMO Net-Zero Framework: Delayed, Not Cancelled
The most consequential near-term development in IMO decarbonization policy isn't CII or EEXI — it's the Net-Zero Framework, the implementation mechanism for IMO's 2023 GHG reduction strategy.
Timeline as it actually stands:
- The framework was agreed in principle at MEPC 83 in April 2025
- Formal adoption, expected via vote, was postponed by one year in October 2025
- The vote is now anticipated at MEPC 84 in April 2026
If adopted, the Net-Zero Framework is expected to apply — consistent with the existing CII precedent — to ships of 5,000 GT and above, meaning it would not directly capture the majority of superyachts in its initial form, in the same way CII does not today.
The Net-Zero Framework's one-year delay is a genuine, confirmed postponement — not a cancellation, and not a signal that IMO's decarbonization trajectory has reversed. Owners and captains should treat 2026 as a monitoring year: MEPC 84 in April 2026 is the concrete date to watch for the framework's formal status, not a date to assume away.
What Actually Governs Superyacht Environmental Compliance Today
With CII and (for most vessels) EEXI and the Net-Zero Framework sitting outside mandatory scope, the binding compliance framework for the typical superyacht remains what it has been: the ISM Code and the flag state's Large Yacht Code (or equivalent), alongside the parts of MARPOL Annex VI that apply regardless of tonnage — sulphur content limits on fuel, NOx emission controls in Emission Control Areas, and general pollution prevention requirements.
This matters for practical compliance planning: a captain preparing for a flag state or Port State Control inspection in 2026 should not expect a CII audit trail to be requested for a sub-5,000 GT vessel, but should expect the usual ISM Code documentation, fuel sulphur content records, and MARPOL Annex VI compliance records that have applied for years.
What This Means for Owners Planning Ahead
Three practical takeaways for owners and management companies thinking about 2026 and beyond:
Confirm your actual GT against both thresholds. Don't estimate exposure from LOA — get written confirmation from your naval architect or classification society of where your vessel sits relative to the 400 GT (EEXI) and 5,000 GT (CII) lines.
Treat SCII as a market decision, not a compliance one. If your charter programme or ownership positioning benefits from a verified environmental performance certification, SCII is a real, credible option developed by a recognised classification society. If not, there is no regulatory pressure forcing the decision in 2026.
Watch MEPC 84 in April 2026. The Net-Zero Framework vote is the single most consequential near-term regulatory event for the broader shipping industry's decarbonization trajectory — and while it's unlikely to directly capture most superyachts on adoption, the direction of travel matters for any owner planning a newbuild or major refit with a multi-decade operating horizon.
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Sources: IMO, EEXI and CII — Frequently Asked Questions (imo.org/en/mediacentre/hottopics/pages/eexi-cii-faq.aspx); IMO Net-Zero Framework FAQ (imo.org); MEPC.338(76); Lloyd's Register, Superyacht Carbon Intensity Indicator (lr.org); SuperyachtNews, 13 May 2025. Regulatory thresholds and timelines are subject to change — confirm current status and vessel-specific applicability with your classification society or flag state administration.
