An Introduction and Practical Guide to Compliant Marine Fuels under MARPOL Annex VI
Fuel oil is the single most important consumable onboard a commercial ship. It affects engine performance, air emissions, operational safety, maintenance costs, and regulatory compliance. Poor-quality or non-compliant fuel can cause serious problems, including engine damage, safety incidents, air pollution, and detention by Port State Control authorities.
Over the past decade, fuel oil quality has become an even more critical issue due to stricter air-emission regulations, particularly the global sulphur limit introduced under MARPOL Annex VI. Ships must now ensure that the fuel they use complies with sulphur limits and other quality requirements, regardless of where they operate.
To support transparency, enforcement, and policy development, the International Maritime Organization (IMO) collects information related to fuel oil quality and availability through the Global Integrated Shipping Information System (GISIS). This is done via the “Fuel Oil Quality” module, which includes information on fuel oil non-availability reports (FONARs) and related issues under MARPOL Annex VI.
This article provides a comprehensive introduction and practical guide to the Fuel Oil Quality option in GISIS. It explains the regulatory background, the purpose of the module, the type of information available, and why it is important for shipowners, fuel suppliers, administrations, inspectors, educators, and maritime professionals worldwide.
Understanding GISIS and Its Role in Air-Emission Compliance
What Is the IMO Global Integrated Shipping Information System?
The IMO GISIS (Global Integrated Shipping Information System) is an online platform managed by the International Maritime Organization that provides transparent and reliable data on ships, companies, flag States, and maritime compliance. It brings together information on safety, security, pollution prevention, port State control, and casualty reports in one place. For seafarers, maritime professionals, researchers, and regulators, IMO GISIS is a trusted tool to check vessel records, track compliance with IMO conventions, and understand global shipping performance. Its free public access supports safer seas, better regulation, and informed decision-making across the maritime industry.
The Fuel Oil Quality module plays a key role in air-pollution control and fuel-market transparency.
Legal Framework: MARPOL Annex VI and Fuel Oil Quality
MARPOL Annex VI Overview
MARPOL Annex VI regulates air pollution from ships. It sets limits on emissions of:
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Sulphur oxides (SOx)
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Nitrogen oxides (NOx)
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Particulate matter
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Ozone-depleting substances
Fuel oil quality is central to these controls, especially for SOx emissions.
The Global Sulphur Limit
Since 1 January 2020, ships operating outside Emission Control Areas (ECAs) must use fuel oil with a sulphur content of not more than 0.50% m/m, unless equivalent compliance methods (such as scrubbers) are used.
Within ECAs, the limit is even stricter, at 0.10% m/m.
Why Fuel Oil Quality Became a Global Issue
Operational and Safety Concerns
The transition to low-sulphur fuels introduced:
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New fuel blends
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Compatibility and stability issues
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Increased risk of fuel contamination
Poor fuel quality can lead to:
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Engine failure
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Loss of propulsion
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Fire and explosion risks
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Increased maintenance and downtime
Compliance and Enforcement Challenges
Ships may face situations where:
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Compliant fuel is not available at a port
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Fuel supplied does not meet specifications
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Documentation is incomplete or inaccurate
These challenges require a structured regulatory response.
What Is Fuel Oil Non-Availability (FONAR)?
Definition of FONAR
A Fuel Oil Non-Availability Report (FONAR) is a report submitted by a ship to its flag State when it cannot obtain compliant fuel oil despite making best efforts.
FONARs are provided for under MARPOL Annex VI, as a means to:
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Document genuine cases of fuel unavailability
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Support fair enforcement
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Improve understanding of fuel supply issues
A FONAR does not automatically exempt a ship from compliance, but it is an important element in enforcement decisions.
Purpose of the Fuel Oil Quality Module in GISIS
Core Objectives
The Fuel Oil Quality module in GISIS aims to:
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Collect information related to fuel oil quality and availability
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Support monitoring of global fuel supply challenges
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Improve transparency on FONAR submissions
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Assist IMO and Member States in policy development
It is a monitoring and governance tool, not a real-time compliance system.
What Information Is Available in the GISIS Fuel Oil Quality Module?
Types of Information Provided
Depending on Member State submissions, the module may include:
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Aggregated information on FONAR cases
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Data related to fuel oil availability issues
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Information supporting analysis of regional supply gaps
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References to MARPOL Annex VI requirements
Individual ship or company commercial details are not publicly disclosed.
Who Submits Fuel Oil Quality Information?
Role of Shipowners and Masters
When compliant fuel is unavailable, the ship’s master and operator:
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Document efforts to obtain compliant fuel
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Submit a FONAR to the flag State
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Retain evidence such as supplier communications
Role of Flag States
Flag States:
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Review FONAR submissions
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Decide on appropriate follow-up actions
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Forward relevant information to the IMO
Role of the IMO
The IMO:
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Collects information from Member States
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Analyzes global trends
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Makes aggregated information available through GISIS
How to Access the Fuel Oil Quality Module in GISIS
Step 1: Access the GISIS Platform
Users access GISIS via the IMO website.
Step 2: Select “Fuel Oil Quality”
From the list of GISIS modules, users select Fuel Oil Quality.
Step 3: Review Available Information
Users can:
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Understand fuel availability challenges
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Support research and policy analysis
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Use the information for education and training
Importance of Fuel Oil Quality Data for Port State Control
PSC Inspections and Fuel Compliance
During PSC inspections, officers may:
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Check bunker delivery notes (BDNs)
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Verify sulphur content documentation
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Examine fuel changeover procedures
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Review any FONAR submissions
GISIS fuel quality data supports consistent enforcement approaches.
Avoiding Unfair Treatment
By understanding fuel availability issues:
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PSC authorities can apply rules more fairly
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Genuine cases can be distinguished from non-compliance
Role in Environmental Protection and Air Quality
Reducing SOx Emissions
Fuel oil sulphur limits significantly reduce:
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Acid rain
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Human health impacts
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Environmental damage near coasts and ports
Fuel quality compliance is therefore a major environmental achievement.
Supporting Global Air-Quality Goals
GISIS fuel quality information supports:
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Monitoring of regulation effectiveness
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Identification of problem areas
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Long-term policy refinement
Practical Use Cases of the Fuel Oil Quality Module
Shipowners and Operators
Operators use fuel quality information to:
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Improve fuel procurement strategies
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Understand compliance expectations
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Reduce enforcement risks
Fuel Suppliers and Port Authorities
Suppliers and ports benefit indirectly from:
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Transparency on availability challenges
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Identification of supply gaps
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Better planning and investment decisions
Policymakers and Researchers
Researchers use GISIS data to:
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Analyze impacts of sulphur regulations
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Study fuel market adaptation
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Support evidence-based decision-making
Relationship with Other GISIS Modules
The Fuel Oil Quality module complements:
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Ship Fuel Oil Consumption – energy and emissions data
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Pollution Prevention Equipment – scrubbers and alternatives
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Port State Control – enforcement outcomes
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Marine Casualties and Incidents – fuel-related safety issues
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Status of Treaties – applicability of MARPOL Annex VI
Together, these modules provide a complete picture of air-emission governance.
Common Misunderstandings about FONAR and Fuel Quality
FONAR Is Not an Automatic Exemption
Submitting a FONAR does not:
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Guarantee acceptance by PSC
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Allow unlimited use of non-compliant fuel
It is only one element considered during enforcement.
Fuel Quality Is Not Only About Sulphur
Fuel oil quality also involves:
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Stability
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Compatibility
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Contamination
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Flashpoint and safety parameters
Best Practices for Using the GISIS Fuel Oil Quality Module
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Use it as an official reference source
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Understand MARPOL Annex VI obligations
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Integrate fuel quality awareness into training programs
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Combine GISIS data with PSC and bunker quality guidance
Educational Value for Maritime Training and Academia
For maritime education, the Fuel Oil Quality module provides:
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Real-world context for air-pollution regulation
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Insight into fuel management challenges
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Understanding of enforcement and compliance mechanisms
It is especially useful in courses on:
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Marine environmental protection
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Ship operations and engineering
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Maritime law
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Energy management and emissions control
Fuel Oil Quality in the Future of Shipping
Transition to New Fuels
As shipping moves toward:
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LNG
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Methanol
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Ammonia
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Biofuels
Fuel quality governance will remain essential, even as fuel types change.
Digitalisation and Reporting
Future developments may include:
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Improved digital bunker documentation
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Enhanced fuel traceability
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Stronger data integration with emissions monitoring
GISIS provides a foundation for this evolution.
Conclusion: Ensuring Clean Air through Transparent Fuel Governance
The Fuel Oil Quality option in the IMO Global Integrated Shipping Information System plays a crucial role in supporting the effective implementation of MARPOL Annex VI. By collecting and presenting information related to fuel quality and non-availability of compliant fuel, the module strengthens transparency, fairness, and environmental protection across global shipping.
For shipowners, administrations, inspectors, educators, researchers, and students, the GISIS Fuel Oil Quality module offers a trusted window into one of the most significant regulatory changes in modern maritime history.
As the industry continues its transition toward cleaner energy and lower emissions, fuel quality governance—supported by tools like GISIS—will remain essential for ensuring that environmental ambition translates into real improvements in air quality and human health worldwide.
