MARPOL requirements for oil record book entries mandate that specific shipboard operations involving oil or oily mixtures be recorded in a standardized logbook, with entries signed by the officer in charge and countersigned by the master. These rules apply under MARPOL Annex I to all ships of 400 gross tonnage and above, as well as all oil tankers of 150 gross tonnage and above. The sections below address the most common compliance questions captains and vessel operators face in 2026.
What operations must be recorded in the oil record book?
Under MARPOL Annex I, the oil record book requires entries for every operation involving oil or oily water on board. For machinery space operations (Part I), this includes taking on fuel oil and lubricating oil, internal transfers of oil, discharge of bilge water, disposal of oily residues (sludge), and ballasting or cleaning of fuel oil tanks. For oil tankers, Part II covers cargo and ballast operations.
Specifically, Part II entries must be made for:
- Loading of oil cargo
- Internal transfer of oil cargo during voyage
- Unloading of oil cargo
- Ballasting of cargo tanks and dedicated clean ballast tanks
- Cleaning of cargo tanks, including crude oil washing
- Discharge of dirty ballast or cleaning water from cargo tanks
- Discharge of water from slop tanks
- Disposal of residues and oily mixtures not otherwise covered
- Discharge overboard or disposal of bilge water accumulated in cargo areas
Each entry must be made promptly after the operation is completed, not at the end of the day or voyage. The International Maritime Organization (IMO) requires entries to be clear, legible, and completed in the official language of the flag state, with an English or French translation if the flag state language is neither.
Who is responsible for signing oil record book entries?
The officer in charge of the operation is responsible for signing each individual oil record book entry at the time it is made. The master of the vessel is then required to countersign each completed page. This dual-signature requirement is a deliberate compliance control: it confirms both that the operation occurred as recorded and that the master is aware of all oil-related activities on board.
In practice, this means the chief engineer typically signs Part I entries covering machinery space operations, while the chief officer or cargo officer signs Part II entries for tanker cargo and ballast operations. The master’s countersignature does not transfer responsibility from the officer who made the entry, but it does establish the master’s oversight role and accountability under port state control inspections.
Delegation of signing authority to unlicensed crew is not permitted. Only certified officers with direct knowledge of the operation may sign entries, and any attempt to have another person sign on an officer’s behalf creates a serious compliance risk.
How long must an oil record book be kept on board?
A completed oil record book must be retained on board the vessel for a minimum of three years after the date of the last entry. This applies to both Part I (machinery space) and Part II (cargo and ballast) record books for oil tankers. During this retention period, the book must be available for inspection by port state control officers at any time.
In practical terms, vessels often carry more than one completed ORB on board at any given time, since a new book begins when the previous one is full. Keeping all books within the three-year window readily accessible, not stored in archives ashore, is a common compliance point that inspectors check. Some flag states impose stricter retention requirements, so operators should verify the rules applicable to their vessel’s flag.
What are the consequences of incorrect or missing ORB entries?
Incorrect, incomplete, or missing oil record book entries are treated as serious MARPOL violations and can result in substantial fines, vessel detention, and criminal prosecution of the master and responsible officers. Port state control authorities in major port states, including those in the Netherlands, Belgium, and Germany, actively inspect ORBs and cross-reference entries against physical evidence on board.
Common violations that trigger enforcement action include:
- Missing entries for operations that clearly took place (evidenced by tank soundings or pump logs)
- Entries made after the fact or backdated
- Inaccurate quantities recorded for discharges or transfers
- Failure to record an overboard discharge, even one that occurred in an emergency
- Unsigned or uncountersigned entries
In several jurisdictions, falsification of the oil record book is treated as a criminal offense separate from the underlying pollution violation. Masters have faced personal prosecution and imprisonment for deliberate record falsification, even when no actual discharge occurred. The reputational and operational cost of vessel detention in a busy port such as Rotterdam or Antwerp can far exceed any fine, making accurate record-keeping a direct operational priority.
How do degassing operations relate to MARPOL record-keeping?
Degassing operations on chemical or oil tankers do not fall directly under MARPOL Annex I oil record book requirements, but they intersect with MARPOL compliance in important ways. When a tanker is degassing cargo residues or vapors that contain oil-derived compounds, any associated discharge of oily water or residues must still be recorded in the ORB. The degassing process itself may also be subject to separate national regulations governing vapor emissions in port areas.
For inland and seagoing tankers operating in northwest European waters, the regulatory picture in 2026 is increasingly strict. The CDNI (Convention on the Collection, Deposit and Reception of Waste from Rhine Navigation) and national regulations in the Netherlands and Belgium impose specific requirements on where and how degassing may take place, with open-air degassing of certain substances now prohibited or heavily restricted in many ports. These rules operate alongside MARPOL, not instead of it.
Captains who need to degas quickly and legally before accepting a new cargo load benefit from purpose-built degassing facilities that handle vapor treatment on site, eliminating the risk of an unrecorded or non-compliant discharge. Using a certified facility also creates a clear documentary record that supports MARPOL compliance and satisfies port state control requirements, reducing the risk of delays or fines that an incomplete or disputed ORB entry might otherwise cause.
How SuperFlox supports compliant oil record book management
Maintaining a clean, complete, and defensible oil record book is easier when the operations that feed into it are handled through certified, documented processes from the outset. SuperFlox specializes in mobile degassing solutions that directly reduce the compliance burden associated with ORB entries for tanker operators working in northwest European ports and inland waterways. Here is how SuperFlox helps in practice:
- Certified vapor treatment on site: SuperFlox’s mobile containerized degassing units treat cargo vapors at the source, ensuring that no unrecorded or non-compliant discharge takes place during the degassing process.
- Clear documentary evidence: Every degassing service generates a service record that operators can attach to their ORB documentation, giving port state control inspectors a verifiable paper trail that closes gaps in the compliance record.
- Flexible deployment: Units can be deployed directly at the terminal or berth where the vessel is located, minimizing turnaround time and allowing captains to degas legally before accepting a new cargo without losing operational time.
- Regulatory alignment: SuperFlox operates in accordance with MARPOL Annex I, CDNI requirements, and national regulations in the Netherlands and Belgium, so operators can be confident that the service meets the standards port state control authorities apply.
- Reduced detention risk: By replacing open-air degassing with a controlled, documented process, SuperFlox removes one of the most common sources of disputed or missing ORB entries that lead to vessel detention.
If your vessel operates in northwest European waters and you want to ensure that every degassing operation is fully documented and MARPOL-compliant, contact SuperFlox today to discuss deployment options at your next port of call.