Ballast Water Management
Managing ballast water under the D-2 standard and the new record book format in force since 2025.
Operational Explanation
Ballast water management prevents the transfer of invasive aquatic species between different ecosystems. Ships must treat ballast water through a Ballast Water Management System (BWMS) compliant with the D-2 standard. Since 8 September 2024, regulation B-3 as amended by Res. MEPC.297(72) requires D-2 of all ships: high-seas exchange under the D-1 standard is no longer an ordinary means of compliance, and the transitional period is over.
Regulatory update: since 1 February 2025 the new Ballast Water Record Book (BWRB) format has been in force, with standardised operation codes A to H (Resolution MEPC.369(80)), similar in style to the Oil Record Book. Since 1 October 2025, an electronic record book must be specifically approved by the flag Administration.
MEPC 84 update (April 2026): the Committee approved draft amendments to the BWM Convention aimed at strengthening its implementation without introducing new regulatory concepts: clarifications on the application of contingency measures, more explicit requirements on the content and approval of Ballast Water Management Plans (BWMP), clearer expectations on crew familiarization and system maintenance/record-keeping, and refined survey and certification provisions, including greater clarity on the transition from prototype (D-4) systems to full D-2 compliance. The Committee also adopted the 2026 Guidelines (G4) for ballast water management and the development of BWMPs, aligned with the new requirements. The IMO Secretariat will prepare the revised consolidated Annex to the Convention, with formal adoption expected at MEPC 85 (30 November–3 December 2026); the transitional non-penalisation approach will end when the amendments enter into force, expected in 2028.
Regulatory Reference
Ballast Water Management Convention, Appendix II (BWRB format updated by Resolution MEPC.369(80), in force since 1 February 2025). Guidance in BWM.2/Circ.80/Rev.1, “2024 Guidance on ballast water record-keeping and reporting”, approved by MEPC 82 on 24 October 2024, whose paragraph 4 states: “This circular revokes BWM.2/Circ.80”. The revision adds the recording in the BWRB of operational scenarios involving challenging water quality, in line with Res. MEPC.387(81). Citing the version without Rev.1 points the reader to a revoked text. Draft amendments to the Convention approved at MEPC 84 (April 2026), revised consolidated Annex expected for adoption at MEPC 85 (30 November–3 December 2026), entry into force expected in 2028; 2026 Guidelines (G4) already adopted.
Scope of Application
The Convention does not contain a criterion of “ballasting/deballasting operations in international waters”. The phrase does not appear in Article 3, and the Convention applies to ships that never leave the waters of a Party too.
The real criterion is twofold. Article 3.1 looks to flag and authority: the Convention applies to ships “entitled to fly the flag of a Party” and to those that “operate under the authority of a Party”. Article 3.2 then lists the exclusions, and they are exhaustive: ships not designed or constructed to carry ballast water; ships of a Party operating only in that Party's waters, unless the Party itself determines the discharge would cause harm; ships operating only in the waters of another Party, subject to that Party's authorization; ships operating only in the waters of one Party and on the high seas, with the same reservation; warships, naval auxiliaries and other State-owned ships on non-commercial service; and permanent ballast water in sealed tanks not subject to discharge.
And the D-2 standard, which this page named without ever quantifying. Regulation D-2 requires a discharge of “less than 10 viable organisms per cubic metre greater than or equal to 50 micrometres in minimum dimension” and “less than 10 viable organisms per millilitre less than 50 micrometres in minimum dimension and greater than or equal to 10 micrometres”. On indicator microbes: toxicogenic Vibrio cholerae (O1 and O139) below 1 colony forming unit per 100 ml, Escherichia coli below 250 cfu per 100 ml, intestinal Enterococci below 100 cfu per 100 ml. Declared limit: the BWM Convention text has no copy that opens on the IMO domain; these transcriptions come from two independent reproductions of the conference text, concurring word for word.
Procedure / How to Complete It
- Identify the operation code (A-H) corresponding to the ballast operation to be recorded, under the new 2025 format.
- Record date, position, volume and method (D-2 compliant BWMS treatment). A D-1 exchange can appear only in documented exceptional situations, not as an ordinary management method.
- Check zone compliance: some coastal or port areas impose additional restrictions.
- Keep the records on board for 2 years and under the company's control for a further 3 years.
- If using an electronic record book, verify it has been approved by the flag Administration (mandatory since 1 October 2025).
- Monitor the evolution of the BWM Convention amendments approved at MEPC 84, in particular on BWMPs, crew familiarization and the transition from prototype D-4 systems to full D-2 compliance.
Practical Example
Ballasting is not Code D. In the format of res. MEPC.369(80) the uptake of ballast water is code (A) — “When ballast water is taken on board from the aquatic environment (ballasting operation)” — while code (D) is something else entirely: “Uptake or discharge of ballast water from/to a port-based or reception facility”.
The eight letters in full: (A) uptake from the aquatic environment; (B) discharge into the aquatic environment; (C) exchange, internal circulation or in-tank treatment; (D) uptake or discharge from or to a port-based or reception facility; (E) accidental discharge or ingress, and any exceptional uptake or discharge; (F) failures and inoperabilities of the BWMS; (G) ballast tank cleaning and flushing, removal and disposal of sediments; (H) additional operational procedures and general remarks.
Example entry, rewritten: "2026-08-01, Code A (ballast water uptake), Item .1 start 06:10 in position 38°10'N 015°30'E; Item .2 completion 07:45, minimum depth of water during uptake 42 m; Item .3 tanks 3P and 3S; Item .4 volume taken 850 m³, total retained after the operation 2,140 m³; Item .5 conducted in accordance with the approved Ballast Water Management Plan; Item .6 treatment method: BWMS active on uptake."
What Typically Goes Wrong
Common Mistakes Mistake Library
| Mistake | Consequence | How to avoid it |
|---|---|---|
| Use of the old BWRB format after 1 February 2025 | PSC deficiency for non-compliance with the new standard | Update forms and crew training before the applicability date |
| Electronic record book not approved by the Flag | Non-compliance from 1 October 2025 | Request specific approval in advance |
| D-1 exchange treated as a still-available alternative, when since 8 September 2024 D-2 applies to all ships | Violation of the applicable standard | Check coastal/regional requirements before the operation |
What the PSCO Checks
Operational Tips
- Update onboard forms to the new BWRB format before every inspection.
- Check the approval status of your BWMS and the related International Ballast Water Management Certificate (IBWMC) documentation.
- Train the crew on the new A-H operation codes.
Preparation checklist
Educational checklist. This summary supports learning and preparation only. It does not replace the vessel’s approved procedures, manuals, statutory documents, company SMS, or applicable official requirements. Completing it demonstrates neither compliance nor readiness for an inspection: it shows that a list has been read, not that the ship is in order. Always verify the current documents carried on board.
- BWRB in the new 2025 format
- Valid International Ballast Water Management Certificate (IBWMC) on board
- Electronic record book approved by the Flag (if in use)
- Crew training on the A-H codes up to date
- Developments in the BWM Convention amendments (MEPC 84/85) and the new 2026 Guidelines (G4) monitored
FAQ
Related Topics
Last substantive revision of this page: 19 August 2026 · page fingerprint 9a8e37ae362f