International Convention for the Prevention of Pollution from Ships (MARPOL)
Status: In force — six annexes governing pollution prevention, from oil record books to the CII carbon-intensity framework under Annex VI.
What Is It?
MARPOL is the principal international convention for preventing pollution of the marine environment from ships, covering both operational discharges and accidental pollution. Its six technical annexes regulate oil (Annex I), noxious liquid substances (Annex II), harmful packaged substances (Annex III), sewage (Annex IV), garbage (Annex V), and air pollution and energy efficiency (Annex VI). Together they define the day-to-day environmental operating rules for virtually every commercial vessel afloat.
Annex I drives some of the most scrutinized recordkeeping in shipping: the Oil Record Book, in which every internal oil transfer, discharge, and disposal operation must be documented in the prescribed format. Oil Record Book deficiencies and falsification remain among the most common causes of port state control detentions and criminal prosecutions worldwide — the notorious "magic pipe" cases. Annex V imposes equivalent discipline through the Garbage Record Book and garbage management plans.
Annex VI has become the convention's most dynamic frontier. Beyond emission control areas (ECAs) and the 0.50% global sulphur cap, it now carries the IMO's energy-efficiency and carbon-intensity framework: the EEXI technical requirement, the operational Carbon Intensity Indicator (CII) with annual A-E ratings, and the SEEMP Part III with its mandatory implementation audits. With the Mediterranean SOx ECA effective from May 2025 and CII reduction factors tightening annually, Annex VI compliance is now a continuous operational discipline rather than a periodic certification exercise.
Who It Affects
MARPOL applies to virtually all commercial vessels, with annex-specific applicability thresholds — Annex I from 150 GT for tankers and 400 GT for other ships, Annex VI generally from 400 GT with the energy-efficiency framework applying to vessels of 5,000 GT and above. Flag states enforce the convention through certification and surveys, while port state control regimes inspect compliance at every call. Owners, operators, technical managers, masters, and engine-room officers all carry direct responsibilities, and the DOC holder's safety management system must embed MARPOL procedures under the ISM Code.
Key Dates
MARPOL 73/78 enters into force (Annexes I and II)
Annex VI (air pollution) enters into force
Global 0.50% sulphur cap on marine fuels takes effect
EEXI, CII rating scheme, and enhanced SEEMP requirements enter into force under Annex VI
Mediterranean Sea SOx Emission Control Area effective — 0.10% sulphur limit
CII reduction factors continue annual tightening toward the 2030 checkpoint
Requirements
- Maintain a compliant Oil Record Book (Parts I and II where applicable) documenting every oil transfer, discharge, and disposal in the prescribed entry codes
- Maintain the Garbage Record Book and implement a garbage management plan under Annex V
- Hold valid IOPP, IAPP, ISPP, and related certificates with survey windows observed
- Comply with fuel sulphur limits globally (0.50%) and in ECAs (0.10%), retaining bunker delivery notes and fuel samples
- Maintain an approved EEXI technical file demonstrating attained EEXI within required limits
- Monitor and report annual carbon intensity, achieve the required CII rating, and implement corrective action plans for D/E-rated vessels
- Carry an approved SEEMP Part III and complete the associated implementation audits
- Observe annex-specific discharge criteria, special-area restrictions, and reception-facility procedures
Penalties & Non-Compliance
MARPOL violations are prosecuted under national law and can be severe. Oil Record Book falsification has produced multi-million dollar corporate fines and imprisonment of officers, particularly under the US APPS regime, alongside vessel banning and debarment. Port state control detentions for MARPOL deficiencies directly hit vessel earnings and inspection targeting profiles. Under Annex VI, vessels rated D for three consecutive years or E in a single year must submit an approved corrective action plan before continuing to trade, and fuel sulphur violations attract fines and detention in ECAs — with charterers increasingly excluding non-compliant tonnage.
How CyberSmart Helps
These modules directly support your MARPOL compliance workflow.
Turn MARPOL into a managed workflow
See how CyberSmart codifies MARPOL into rules, keeps electronic record books audit-ready, and tracks CII across your fleet.