Extended Operational and Trade Vocabulary

IMO GHG Strategy, CII, EEXI and EU Maritime Regulation glossary

The GHG-strategy and EU-regulation vocabulary: the Poseidon Principles and Sea Cargo Charter signatories, accredited verifiers under EU MRV Regulation (EU) 2015/757, the CII, EEXI, and ETS analytics platforms, and the GHG-reporting terms. Grounds each term in the IMO efficiency measure or the EU maritime regulation it belongs to.

204 defined terms.

A

ABN AMRO: Dutch bank historically active in shipping lending, which scaled back its global shipping portfolio in the 2020s.
ABS Eagle Insights: Digital platform from the American Bureau of Shipping that delivers CII, EEXI, and EU MRV/ETS analytics for owners and managers.
Accredited verifier: Body accredited to ISO 14065 or ISO 17029 authorized to verify EU MRV, EU ETS, and FuelEU Maritime data.
ADM: Archer Daniels Midland, the agricultural processor whose ARTCO subsidiary operates one of the largest US grain barge fleets.
AER: Annual Efficiency Ratio expressed in grams of CO2 per deadweight-ton-nautical-mile, the default carbon intensity metric used for CII rating under MEPC.336(76).
Air Lubrication System: Technology that injects compressed air beneath a hull to reduce frictional resistance, typically delivering 5 to 10 percent fuel savings.
Alternative Maritime Power: Shore power program initiated by the Port of Los Angeles in 2004 to allow berthed vessels to shut down auxiliary engines.
Ammonia: Carbon-free marine fuel with a tank-to-wake carbon factor of zero under IMO MEPC.376(80), with upstream emissions accounted separately.
Annex VI: Regulations for the Prevention of Air Pollution from Ships.
Argonaut: Bureau Veritas software suite for fleet performance and CII compliance monitoring.
Attained CII: Operational carbon intensity actually achieved by a ship over a calendar year, compared against the Required CII to produce a rating from A to E.
Attained EEDI: Calculated carbon dioxide emissions per transport work for a newbuild ship, verified at preliminary and sea trial stages under MEPC.245(66).
Auxiliary Engine Power: Power consumed by generators and supporting machinery, included in EEDI and CII calculations through prescribed correction factors.

B

B24: Bunker blend of approximately 24 percent biofuel with VLSFO base, commonly sold as VLSFO-B24 in Singapore and Rotterdam.
B30: Blend of about 30 percent biofuel with conventional MGO or VLSFO used in commercial marine bunkering.
BAR Technologies: United Kingdom engineering firm that developed the WindWings wing sail deployed on the Pyxis Ocean in 2023.
Baseline (2008): Reference year for IMO GHG reduction percentages under MEPC.304(72) and MEPC.377(80).
Becker Mewis Duct: Pre-swirl wake-equalizing duct with internal fins, developed by Becker Marine Systems, fitted ahead of the propeller.
Biofuel: Liquid or gaseous fuel from biomass; covered by ISCC EU or RED II certification for FuelEU.
Biomethane: Renewable natural gas produced from anaerobic digestion of organic feedstock, interchangeable with LNG in dual-fuel engines.
Biomethanol: Methanol produced from biomass with a substantially lower well-to-wake carbon intensity than fossil methanol.
BNP Paribas: French bank with a global shipping finance platform serving major international owners.
BSR: Business for Social Responsibility, manager of the Clean Cargo Working Group emissions reporting framework since 2003.
Bulk Carrier: Single-deck ship for unpackaged dry bulk.
Bureau Veritas: French classification society delegated by some flag States to approve MET programs and issue MLC certificates.
BV Energetics: Bureau Veritas digital platform for carbon intensity monitoring and CII forecasting.

C

CARB: California Air Resources Board, regulator requiring at-berth shore power for container, refrigerated cargo, and cruise ships at California ports since 2014.
Carbon Factor Cf: Conversion factor from grams of fuel consumed to grams of CO2 emitted, standardized in MEPC.376(80).
Carbon Intensity Indicator: Operational carbon metric introduced by MEPC.328(76) effective 1 January 2023 for ships of 5,000 gross tonnage and above.
Carbon Levy: Proposed mid-term economic measure discussed at MEPC 80, 81, and 82 as part of the IMO basket of measures.
Cargill: The agricultural processor whose Cargo Carriers and CGB Enterprises interests participate in inland grain barging.
CCS GreenShip: Decarbonization platform from the China Classification Society for CII, EEXI, and EU compliance reporting.
CCWG: Clean Cargo Working Group, container shipping emissions benchmarking initiative managed by BSR since 2003.
cgDIST: Capacity gross tonnage distance-based reference metric used as an alternative CII reference line for passenger and ro-ro vessels.
Citi: Citigroup, founding Poseidon Principles signatory in 2019.
ClassNK: Nippon Kaiji Kyokai, Japanese classification society and IACS member, founded 1899.
Cofco: Chinese state-owned commodity trader and Sea Cargo Charter signatory.
Cold Ironing: Onshore power supply enabling ships to shut down engines in port.
Container Ship: Ship type with dedicated EEDI Phase 3 30 percent reduction factor and dedicated AER reference line.
Corrective Action Plan: Three-year remediation plan required in SEEMP Part III when a ship is rated D for three consecutive years or E in a single year.
Credit Agricole: French bank and founding Poseidon Principles signatory.
Cruise ship: Passenger cruise vessel.

D

Danish Ship Finance: Specialist Danish lender focused exclusively on ship mortgage finance, funded by covered bonds.
Decarbonisation Insights: DNV digital service providing strategic and regulatory advisory under the Veracity ecosystem.
DNB: Norwegian bank commonly acting as deposit holder in ship sales.
DNV: Det Norske Veritas (DNV); IACS member classification society.
DNV ECO Insight: Det Norske Veritas fleet performance management portal covering fuel and emissions reporting.
Double Counting Bonus: Multiplier of 2 applied to RFNBOs under FuelEU Maritime from 2025 to 2033 to incentivize their uptake.
Dual-fuel engine: Engine running on both liquid and gaseous fuels (e.g., WinGD X-DF).
DVB Bank: German transport finance bank and founding Poseidon Principles signatory.
DWT: Deadweight tonnage; conventional LNG carriers typically 80,000 to 100,000 DWT.

E

E-Methane: Synthetic methane from renewable hydrogen and CO2.
E-Methanol: Methanol synthesized from green hydrogen and captured CO2.
Eagle Insights: ABS digital platform for fleet decarbonization analytics.
Econowind: Dutch supplier of VentiFoil suction sails for wind-assisted propulsion.
EEDI: Energy Efficiency Design Index, MARPOL Annex VI Chapter 4.
EEDI Phase 0: Baseline phase for newbuilds contracted between 1 January 2013 and 31 December 2014.
EEDI Phase 1: Phase requiring 10 percent reduction from the Reference Line for newbuilds from 2015 to 2019.
EEDI Phase 2: Phase requiring 20 percent reduction from the Reference Line for newbuilds from 2020 to 2024.
EEDI Phase 3: Strictest EEDI tier, effective 1 April 2022 for many ship types under MEPC.328(76).
EEDI Reference Line: Logarithmic fit of attained EEDI values for ships built between 1999 and 2009, defined per ship type under MEPC.215(63).
EEXI: Energy Efficiency Existing Ship Index, MARPOL Annex VI Chapter 4.
EEXI Reduction Factor: Required percentage reduction from the EEDI Reference Line, ranging from 15 to 30 percent depending on ship type and size.
EEXI Technical File: Required documentation per MEPC.333(76).
Energetics: Bureau Veritas CII and EU compliance digital service.
Energy Saving Device: Hydrodynamic appendage such as a Mewis Duct or Pre-Swirl Stator installed to reduce propulsive power demand.
Engie: French utility, partner with EDPR in the Ocean Winds offshore wind joint venture.
Engine Power Limitation: Compliance measure under EEXI restricting maximum continuous rating through a physical limiter or software lock-out.
EPL: Acronym for Engine Power Limitation under MEPC.335(76) guidelines.
Equinor: Norwegian operator and partner in the Northern Lights CO2 storage project.
EU Allowance: Tradable unit under the EU ETS equal to one ton of CO2 equivalent, abbreviated EUA.
EU ETS Maritime: Extension of the EU Emissions Trading System to shipping under Directive 2023/959; applies from 1 January 2024 with phased surrender of 40% in 2024, 70% in 2025, and 100% from 2026.
EU MRV: EU Regulation 2015/757 on monitoring, reporting, and verification of CO2 emissions from shipping.
EU TEN-T: Trans-European Transport Network, the EU port and corridor framework that defines OPS deployment obligations under Regulation (EU) 2023/1804.
EUA: EU Allowance representing the right to emit one ton of CO2 equivalent under the EU ETS.
ExxonMobil: International oil company and Sea Cargo Charter signatory.

F

Final Verification: Survey of attained EEDI conducted during sea trials following completion of a newbuild.
Flettner rotor: Wind-assisted propulsion using Magnus effect.
FOBAS: Lloyd's Register Fuel Oil Bunker Analysis and Advisory Service.
Fuel Pool: Mechanism under FuelEU Maritime allowing two or more ships to aggregate compliance balances within a calendar year.
FuelEU Maritime: European Union regulation imposing greenhouse gas intensity limits on shipping fuels, driving development of pooling mechanisms and compliance instruments.

G

Gas carrier: Vessel for liquefied gases such as LNG, LPG, ethane, or ethylene.
gCO2 per dwt-nm: Unit of the AER metric used for CII rating.
gCO2eq per MJ: Unit of greenhouse gas intensity used by FuelEU Maritime, expressing emissions per megajoule of energy used on board.
General Cargo Ship: Multipurpose vessel; lashing arrangements per CSM and CSS Code.
GHG fuel standard: Lifecycle GHG intensity limit on marine fuels, central to the IMO Net-Zero Framework.

H

Heavy Fuel Oil: Bunker fuel grade requiring heated lightering during salvage offload.
Hempaguard: Silicone hydrogel fouling release coating from Hempel typically delivering 2 to 5 percent fuel savings.
HFO: Heavy fuel oil, residual marine fuel grade per ISO 8217 RMG and RMK.
High Voltage Shore Connection: Berth-side equipment that supplies HV shore power to ships in accordance with IEC/IEEE 80005-1.
HVO: Hydrotreated vegetable oil, a drop-in renewable diesel used in inland vessel engines.
Hydrogen: Lightest chemical element used as a marine fuel either as liquid LH2 at minus 253 degrees Celsius or as compressed gas at 700 bar.

I

i4 Insight: Lloyd's Register fleet performance and emissions management platform.
IAPP Certificate: International Air Pollution Prevention Certificate under MARPOL Annex VI.
IEC/IEEE 80005-1: International standard for high voltage shore connection systems at 6.6 kV and 11 kV, 50 or 60 Hz.
ING: Dutch bank and founding Poseidon Principles signatory.
Initial GHG Strategy: IMO strategy adopted by Resolution MEPC.304(72) on 13 April 2018, superseded in 2023 by MEPC.377(80).
Intersleek 1100SR: Silicone fouling release coating from AkzoNobel International typically delivering 2 to 5 percent fuel savings.
Intra-EU voyage: Voyage between two EU ports; 100% of CO2 included in EU ETS Maritime.

J

Jotun SeaQuantum X200: Premium silyl-methacrylate antifouling product within the SeaQuantum range.

K

Kite Skysails: Wind-assisted propulsion system based on a towing kite, developed by SkySails Power.
Klaveness ALS: Air lubrication system developed in collaboration with Klaveness Combination Carriers.

L

LBG: Liquefied Biogas, renewable equivalent of LNG produced from biomethane.
Levels of Ambition: Five targets set by the 2023 Revised IMO GHG Strategy MEPC.377(80) covering carbon intensity, total emissions, and zero or near-zero fuel uptake.
Lloyd's Register: LR, UK-headquartered classification society and IACS member founded 1760.
LNG: Liquefied natural gas; ~-162 C, near atmospheric pressure.
LPG: Propane, butane; carried fully refrigerated, semi-refrigerated, or pressurized.
LR FOBAS: Lloyd's Register Fuel Oil Bunker Analysis Service.

M

Maersk Pelican: LR2 product tanker that became the first commercial vessel fitted with Norsepower Flettner rotors in 2018.
MALS: Mitsubishi Air Lubrication System, an early air lubrication design from Mitsubishi Shipbuilding.
MARPOL Annex VI: Air pollution and energy-efficiency annex.
MDO: Marine diesel oil, distillate fuel per ISO 8217 DMB.
MEPC: Marine Environment Protection Committee.
MEPC.203(62): Resolution of 2011 adopting EEDI and SEEMP amendments to MARPOL Annex VI.
MEPC.245(66): Resolution providing the 2014 Guidelines on the Method of Calculation of the Attained EEDI for new ships.
MEPC.304(72): IMO Initial Strategy on Reduction of GHG Emissions from Ships (2018).
MEPC.328(76): Adoption of MARPOL Annex VI amendments establishing EEXI, CII rating, and enhanced SEEMP.
MEPC.335(76): Guidelines on the shaft or engine power limitation system to comply with the EEXI requirements.
MEPC.336(76): 2021 Guidelines on operational carbon intensity indicators and the calculation methods.
MEPC.337(76): 2021 Guidelines on the reference lines for use with operational carbon intensity indicators.
MEPC.338(76): 2021 Guidelines on the reference lines for use with operational carbon intensity indicators.
MEPC.376(80): IMO guidelines on lifecycle GHG intensity of marine fuels (LCA).
MEPC.377(80): IMO 2023 Revised Strategy on Reduction of GHG Emissions from Ships.
Methanol: IBC Category Y; flammable; common chemical tanker cargo.
Mewis Duct: Pre-swirl wake-equalizing duct developed by Friedrich Mewis and Becker Marine Systems, widely retrofitted on tankers and bulkers.
MGO: Marine gas oil, distillate fuel per ISO 8217 DMA.
Mid-Term Measures: Basket of technical and economic measures including a GHG fuel standard and an emissions pricing mechanism, scheduled for IMO adoption from 2025.
Monitoring Plan: Document submitted under EU MRV setting out the methodology for monitoring CO2 emissions on EU-related voyages.

N

Net-Zero Ambition: Fourth level of ambition of the 2023 Revised IMO GHG Strategy targeting net-zero GHG emissions by or around 2050.
Nordea: Nordic bank used as escrow holder in ship sales.
Norsepower: Finnish manufacturer of Rotor Sails with five Lloyd's Register notations and installations on more than seven vessels.

O

Oceanbird: Wallenius Marine and Stena RoRo wind-assisted vessel concept exploring methanol auxiliary fuel and sail-assisted propulsion.
OPS: Onshore Power Supply, IEC/IEEE/ISO 80005-1 standard.

P

Passenger ship: SOLAS-defined ship carrying more than 12 passengers.
Pelican: Original name of Drake's Golden Hind before his circumnavigation of 1577 to 1580.
Phase 0: EEDI baseline phase from 2013 to 2014.
Phase 1: EEDI phase requiring 10 percent reduction from 2015 to 2019.
Phase 2: EEDI phase requiring 20 percent reduction from 2020 to 2024.
Phase 3: EEDI phase requiring 30 percent reduction from 2025 onward for most ship types.
Pooling Mechanism: Provision under FuelEU Maritime allowing aggregation of compliance balances between ships.
Poseidon Principles: Framework for integrating climate considerations into ship finance.
Poseidon Principles for Marine Insurance: Analogous initiative for marine insurers.
Pre-Duct: Stationary duct fitted upstream of the propeller to recondition inflow and reduce required power.
Pre-swirl stator: Energy-saving device with vanes ahead of propeller.
Preliminary Verification: Initial EEDI verification carried out at the design stage prior to construction.
Propeller polishing: Hull and propeller maintenance reducing roughness and fuel use.
PSS: Peak Season Surcharge, seasonal uplift on transpacific and other peak-demand trades.
Pyxis Ocean: Cargill chartered bulk carrier retrofitted with BAR Technologies WindWings (2023).

Q

Quota Allocation: Issuance of EU Allowances to maritime operators under the surrender obligations of EU ETS Maritime.

R

Rating Bands: Five-tier CII grading from A (Major Superior) through E (Major Inferior) defined in MEPC.338(76).
Reduction Factor X: Percentage in the Required EEDI formula representing the regulatory cut from the Reference Line.
Reduction Factor Z: Percentage in the Required CII formula starting at 5 percent in 2023 and rising annually to 11 percent in 2026.
Reference Line: Curve of carbon intensity values defined per ship type, used to derive required EEDI and required CII.
Regulation (EU) 2015/757: EU Monitoring, Reporting, and Verification regulation for CO2 from maritime transport, in force from 29 April 2015.
Regulation (EU) 2023/1804: Alternative Fuels Infrastructure Regulation defining OPS deployment obligations at TEN-T ports.
Regulation (EU) 2023/1805: FuelEU Maritime Regulation of 13 September 2023 in force from 1 January 2025.
Regulation (EU) 2023/957: Regulation of 10 May 2023 extending the EU ETS to maritime transport from 1 January 2024.
Required CII: Annual reference value calculated using ship-type-specific reference line and Z factor.
Required EEDI: Reference Line value reduced by the X reduction factor for the applicable EEDI phase.
RFNBO: Renewable Fuel of Non-Biological Origin, eligible for the FuelEU double counting bonus from 2025 to 2033.
RINA Cube: Decarbonization and compliance digital service from the Italian classification society RINA.
Ro-pax: roll-on/roll-off passenger ferry.
Rotor Sail: See Flettner Rotor.
Rudder bulb: Streamlined bulb on the rudder leading edge aligned with the propeller hub to recover hub-vortex energy.

S

Sea Cargo Charter: Framework for charterers to align with IMO climate goals.
Sea-Cargo SC Connector: Ro-Ro vessel operated by Sea-Cargo fitted with tilting Norsepower Rotor Sails.
SEEMP: Ship Energy Efficiency Management Plan required for all ships of 400 GT and above under MARPOL Annex VI; Parts II and III apply to ships of 5,000 GT and above.
SEEMP Part I: The Ship Energy Efficiency Management Plan element covering vessel specific measures and procedures for efficient operation.
SEEMP Part II: The fuel oil consumption data collection plan required by IMO MARPOL Annex VI for ships above 5,000 gross tonnage.
SEEMP Part III: The CII implementation plan required under IMO MARPOL Annex VI describing how a ship will achieve its required carbon intensity.
SFOC: Specific Fuel Oil Consumption, the engine fuel consumption per kilowatt-hour used in EEDI and EEXI calculations.
Shell: Oil and gas major with offshore wind interests including Mayflower (now SouthCoast Wind), CrossWind, and Atlantic Shores.
Silverstream Technologies: London-based supplier of air lubrication systems delivering measured 5 to 10 percent fuel savings.
SkySails Power: German developer of automated towing kite systems for wind-assisted propulsion.
Slow Steaming: Operating below design speed to save fuel and reduce emissions.
Societe Generale: French bank and founding Poseidon Principles signatory.
Spiral Boss: Propeller boss cap fin design that reduces hub vortex losses.
Stern Tunnel: Hull form modification channeling flow to the propeller to improve inflow uniformity.
Suction Sail: Wind-assisted device using boundary layer suction over a fixed foil, marketed as VentiFoil by Econowind.

T

Tank-to-Wake: Emissions accounting boundary covering combustion of fuel on board, used as the default EEDI and CII boundary.
Tanker: Ship type subject to dedicated EEDI Reference Line and AER reference line.
TEN-T: Trans-European Transport Network defining the EU port hierarchy for OPS deployment.
THETIS: EMSA-operated PSC database used by Paris MoU.
Total: TotalEnergies, French oil company and Sea Cargo Charter signatory.
Trafigura: Commodities trader that has invested in CO2 shipping and offshore renewable projects.
Transport Work: Product of capacity and distance used as the denominator in EEDI and AER metrics.
Trim Optimization: Operational optimization of draft and trim using CFD-derived performance baselines.

U

ULSFO: Ultra low sulfur fuel oil with maximum 0.10 percent sulfur supplied for use in emission control areas.

V

Ventifoil: Econowind suction wing wind-assist device using boundary-layer suction.
Veracity: DNV digital ecosystem hosting ECO Insight and Decarbonisation Insights applications.
Verifier: Body accredited under EU MRV or under EU ETS Maritime to verify ship emissions data.
Viking Grace: Viking Line LNG dual-fuel cruise-ferry built 2013 and the world's first LNG-fueled passenger cruise-ferry, deployed on Turku to Stockholm.
Vitol: International commodity trader and Sea Cargo Charter signatory.
VLSFO: Very Low Sulfur Fuel Oil with sulfur content at or below 0.5 percent mass, used to meet IMO 2020 outside emission control areas.

W

Wake Equalizing Duct: Annular duct fitted ahead of the propeller to equalize wake and improve propulsive efficiency.
Wallenius Marine: Swedish ro-ro and car carrier operator and partner in the Oceanbird wind-assisted methanol concept.
Well-to-Tank: Upstream lifecycle emissions accounting boundary, addressed separately from tank-to-wake for hydrogen and ammonia under MEPC.376(80).
Well-to-wake: Lifecycle accounting boundary used in FuelEU Maritime greenhouse gas intensity.
WindWings: Wing sail system from BAR Technologies and Yara Marine, deployed on the Pyxis Ocean in 2023.

X

X Reduction Factor: Percentage cut from the EEDI Reference Line that defines the Required EEDI for each ship type and phase.

Y

Year-On-Year Tightening: FuelEU Maritime and CII design feature progressively lowering the allowed greenhouse gas intensity and operational AER through 2050.

Z

Z Reduction Factor: Annual percentage cut applied to the CII Reference Line, set at 5 percent in 2023 and increasing to 11 percent in 2026.
Zero or Near-Zero GHG Fuels: Fifth level of ambition under MEPC.377(80) targeting an uptake of at least 5 percent and striving for 10 percent by 2030.
ZETA: ClassNK suite for CII, EEXI, EU MRV, and EU ETS compliance reporting.