Operational guide · Operational procedure

Ballast Water Management

The BWM Convention: scope, approved plan, standards, records, failures and conditions for alternative measures.

ballast waterBWM ConventionD-2BWRB

Operational Explanation

8 September 2024 ended the ordinary transition to D-2 under amended B-3. D-2 is a performance standard, not the name of a single technical method. D-1 is not a freely available ordinary alternative for a ship subject to D-2. Article 3 scope/exclusions, A-3 exceptions, A-4 exemptions, A-5 equivalent compliance, B-3.6 reception facilities, B-3.7 accepted methods and D-4 regimes remain distinct: verify the basis for the individual case.

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.

A ship-specific approved plan, designated officer and familiarization are existing obligations (B-1/B-6), not requirements awaiting future amendments. MEPC.409(84) adopts the 2026 G4 with an invitation to use them and deferred revocation of earlier guidelines. Draft Convention revisions are not yet in-force provisions.

Non-penalization under MEPC.290(71) §§4–6 concerns D-2 exceedance only on the specified conditions: type-approved, correctly installed and maintained system, BWMP followed, proper self-monitoring indication or defect notified before discharge. It does not automatically protect poor maintenance or restrict port protective powers. Its end depends on actual entry into force of the package, not an already definitive 2028 date.

Regulatory Reference

BWM Convention, article 3 and regulations B-1/B-2/B-3/B-6, D-2 and E-1/E-2: official text in the Dutch treaty register. Transition MEPC.297(72); new BWRB MEPC.369(80); electronic records MEPC.383(81); challenging water quality MEPC.387(81).

Record keeping: BWM.2/Circ.80/Rev.1, circulated on 24 October 2024 after MEPC 82 approval; that is not the Committee session date. Contingency: BWM.2/Circ.62, read with the approved plan and authority decisions.

Scope of Application

Ballast water management is governed by the BWM Convention, separately from MARPOL. Its placement in this module is thematic and does not make the BWRB a MARPOL record book.

The Convention does not require operations to occur in “international waters”. Separate flag/authority, exclusions, exemptions and documentary requirements.

Article 3: distinguish flag/authority and each exclusion. Article 3.2(b) concerns a Party’s ships operating solely in its waters, unless it determines a risk; 3.2(c) concerns a Party’s ships solely in another Party’s waters with the latter’s authorization. Article 3.2(d) concerns operation solely in one Party’s waters and on the high seas, excludes ships refused authorization under (c), and preserves the Party’s risk determination. Do not turn these branches into a general cabotage exemption. The other 3.2 exclusions and 3.3 no-more-favourable-treatment rule remain.

D-2 (size classes refer to the organism’s minimum dimension): fewer than 10 viable organisms ≥50 μm per m³ and fewer than 10 viable organisms from 10 to <50 μm per ml. Indicators: toxigenic Vibrio cholerae O1/O139 <1 cfu/100 ml or <1 cfu/g of zooplankton samples (wet weight); E. coli <250 cfu/100 ml; intestinal enterococci <100 cfu/100 ml. These are performance criteria assessed through relevant methods, not a single BWMS status light.

Procedure / How to Complete It

Before operating: approved BWMP, designated officer, familiarization, sequences and safety, sediment management, system manual/limits/maintenance. Distinguish BWMS type approval, installation evidence and the ship certificate.
Failure or problematic water: follow the approved BWMP and manual, contact the port State and flag as appropriate, and agree the measure before discharge. Retention, reception, exchange or alternative treatment are not unilateral options: the solution must be acceptable to the port State. For challenging water quality, bypass is a last resort after checks and mitigation, followed by decontamination, records and information to the State receiving the discharge. Not every salinity/temperature limit is this situation.
Make entries in the ship’s working language; if it is not English, French or Spanish, include a translation into one of those languages (B-2.5). Use A–H codes in the current format and the tank identification diagram. Enter every applicable field without delay using a consistent time reference.
The officer in charge signs each operation; the master signs completed pages or groups of electronic records. Retain for two years on board after the last entry, then at least three years under company control.
For electronic records check the approval required from 1 October 2025. Apply E-1/E-2 to surveys/IBWMC: ordinary ≥400 GT regime except platforms, FSUs and FPSOs; the Administration sets appropriate measures for other ships, not an absence of obligations.

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, treatment through 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.

Training example; coordinates and depth are assumed, not verified hydrographic data: 01 AUG 2026, code A; .1 start 06:10 UTC, 38°10′ N 015°30′ E; .2 end 07:45 UTC, 38°12′ N 015°32′ E, minimum water depth during uptake 42 m; .3 tanks 3P/3S; .4 volume taken 850 m³, total on board 2,140 m³; .5 operation in accordance with approved BWMP; .6 BWMS treatment during uptake. Officer-in-charge signature; master’s signature on completed page/group.

What Typically Goes Wrong

An up-to-date record format does not cure incorrect ballast management. The plan, system, operations and communications must describe the same event.

Common Mistakes Mistake Library

Avoid unilateral D-1 after failure, preventive bypass based on a previous port difficulty, postponing plan/familiarization until future amendments, confusing BWMS approval with the IBWMC, or omitting final position A.2.

What the PSCO Checks

A PSCO may check implementation of the BWMP, familiarization, system limits/maintenance, required certificate, BWRB and contingency communications. The new book is not the sole element of preparation.

Operational Tips

Prepare contingency arrangements and contacts before operating.
Check actual limits and maintenance, not just type approval.
Check A–H, tank diagram, signatures and 2+3-year retention.

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.

Approved BWMP, designated officer and familiarized crew
Manuals, sediments, limits and maintenance checked
Ship certificate distinguished from BWMS type approval/installation
Contingency agreed before discharge; CWQ bypass only as last resort
Complete 2025 BWRB, signatures, tank diagram and 2+3 retention
Electronic record book approved if used

FAQ

May I discharge after recording the failure?

No: recording does not authorize discharge. Follow the plan and agree an acceptable measure with the port and relevant authorities before operating.

Is non-penalization immunity?

No. MEPC.290(71) conditions it on approval, correct installation/maintenance, plan implementation and self-monitoring or prior notification; port protective powers remain.

Are the plan and training future obligations?

No: B-1 and B-6 already require them. Distinguish the existing obligation from 2026 G4 and amendments still awaiting adoption.