Anti-Fouling Systems Convention - Hull Coatings and Compliance Requirements

Authority. Issued by the Maritime Administrator in the exercise of applicable functions under the Maritime Act [CAP 131], as amended in 2025. Read this circular with the Convention, its amendments in force and applicable VISR instructions.

1. Background and Purpose

Anti-fouling coatings help prevent algae, barnacles and other marine organisms from attaching to a vessel’s underwater surfaces. They help maintain the vessel’s performance and reduce fuel consumption. Some substances used in these coatings, however, can escape into the water and cause lasting harm to marine life. The Convention controls those harmful substances while allowing owners to use compliant anti-fouling systems.

The International Convention on the Control of Harmful Anti-fouling Systems on Ships, 2001 (AFS Convention), has been in force for Vanuatu since 20 November 2008, following accession on 20 August 2008. These are existing obligations. This circular explains how owners must demonstrate compliance, including with the controls on cybutryne that took effect on 1 January 2023. (IMO status of conventions, 30 October 2026, AFS entry for Vanuatu) (IMO resolution MEPC.331(76))

Owners must establish which coatings are present on each vessel, check the supporting records and arrange necessary surveys or corrective work with VISR or its authorized Recognized Organization (RO), as applicable. A paint description such as “TBT-free” does not, by itself, establish compliance with the separate cybutryne controls. The reporting period in section 8 does not extend any existing compliance deadline.

2. Vessels and Systems Covered

The Convention applies broadly to Vanuatu-flagged vessels operating in the marine environment, including fishing and offshore vessels, subject to its express exceptions. “Anti-fouling system” includes paints, coatings, surface treatments and devices used to prevent unwanted organisms attaching. The 400 gross tonnage (GT) and 24-metre thresholds in section 5 determine documentation requirements; smaller size does not give general permission to use prohibited substances. (AFS Convention, articles 2–4 and annex 4)

Fixed and floating platforms, floating storage units (FSUs) and floating production, storage and offloading units (FPSOs) have specific treatment under the Convention. Owners must confirm the relevant controls and, where applicable, coastal State jurisdiction with VISR. The exclusions from the standard certificate regime do not remove all substance controls.

3. Organotin Compounds Including TBT

Do not apply or reapply organotin compounds that act as biocides in anti-fouling systems. This includes tributyltin (TBT). A biocide is a substance used to kill or inhibit organisms; the restriction concerns organotin compounds performing that function. (AFS Convention, annex 1)

Where these prohibited compounds remain in an older coating on the hull or external parts or surfaces, the vessel must comply with the requirement to remove the system or maintain an effective barrier coating that prevents the compounds leaching into the water. The longstanding removal or sealing requirement is already applicable; owners must not treat the next planned docking as a new grace period.

Annex 1 contains a narrow exception to the organotin removal or sealing requirement for platforms, FSUs and FPSOs constructed before 1 January 2003 that have not been in dry dock on or after that date. It does not permit new application of prohibited organotin compounds. Provide construction and docking records to VISR before relying on this provision.

4. Cybutryne Controls and Deadlines

Cybutryne, CAS number 28159-98-0, is a separate biocide controlled by the Convention. Since 1 January 2023, ships must not apply or reapply an anti-fouling system containing it. This prohibition applies irrespective of the limited exceptions to removal or sealing described below. (Annex 1, as amended by IMO resolution MEPC.331(76))

For vessels that had cybutryne in the external coating layer of the hull or external parts or surfaces on 1 January 2023, the affected system must be removed or covered by an effective barrier coating at the next scheduled renewal of the anti-fouling system after that date, and in any event no later than 60 months after its last application. The earlier applicable date governs.

Example: if the last cybutryne application was on 15 June 2022, the 60-month limit falls on 15 June 2027. If the next scheduled renewal is on 1 May 2027, removal or sealing is required at that renewal. Owners cannot assume that every vessel has until the end of 2027, and a later docking booking does not extend the 60-month limit.

The cybutryne removal or sealing requirement does not apply to the following categories under annex 1:

a. Platforms, FSUs and FPSOs constructed before 1 January 2023 that have not been in dry dock on or after that date.

b. Ships not engaged in international voyages.

c. Ships below 400 GT on international voyages, only if the coastal State or States concerned accept the exception.

These exceptions do not authorize fresh application of cybutryne. Owners claiming an exception must give VISR the vessel’s operating history and supporting evidence, including coastal State acceptance where required. Review the position before a change of trade or docking that affects eligibility.

A barrier coating must be suitable for the underlying system and verified as effectively covering it. Ordinary overpainting is not sufficient evidence of sealing. If the coating history or the relevant application date is uncertain, obtain the manufacturer’s and yard’s records and refer the matter to VISR and the responsible RO. Do not substitute an assumed date for missing evidence.

5. Certificate or Declaration Required on Board

The following requirements apply to vessels covered by the Convention. An international voyage includes a voyage to or from another State’s port, shipyard or offshore terminal. Length is the Convention measurement, based on the Load Lines definition; use the vessel’s verified particulars.

References: annex 4, regulations 1, 2 and 5; appendices 1 and 2

The declaration must follow the Convention’s model and be available in at least English, French or Spanish. A manufacturer’s product declaration is supporting evidence; it does not replace the vessel’s required certificate or owner’s declaration.

6. Surveys and the Updated Certificate

For vessels requiring a certificate, arrange an initial survey and a survey when the anti-fouling system is changed or replaced. Keep the certificate and Record properly updated. The Convention does not prescribe a routine annual or five-year renewal cycle for this certificate, but it ceases to be valid after a change or replacement without the required endorsement, or on transfer to another flag. (Annex 4, regulations 1–4)

Agree the survey arrangements with the authorized RO before coating work starts. IMO guidance generally treats repairs affecting about 25% or more of the system as a change or replacement. Smaller repairs must still use compliant products and be documented; ask the RO to confirm the survey implications of the proposed work. (IMO resolution MEPC.358(78), paragraphs 3.2–3.5)

Ships affected by the cybutryne amendments were required to obtain certification in the amended form within 24 months of 1 January 2023. That period ended on 1 January 2025. For ships confirmed not to be affected, resolution MEPC.331(76) provides for the amended certificate at the next anti-fouling system application. Owners must have their RO verify the correct certificate position and report any overdue action immediately. (MEPC.331(76), paragraphs 4–5 and amended annex 4 regulation 2(3))

The updated certificate identifies the applicable compliance option, including any permitted deadline for removing or sealing an existing cybutryne coating. Issuing a certificate does not extend that deadline. A pre-2023 form should be assessed against the vessel’s actual coating history and the transition provisions, rather than treated as proof of compliance or automatically rejected solely because of its age.

7. Coating Work and Supporting Evidence

Owners and managers must give the yard, coating contractor and responsible RO clear instructions before work begins. The vessel’s file must show what was applied, where and when, and how compliance was verified.

1. Check the product before application. Obtain the manufacturer’s declaration addressing the Convention as amended, including organotin biocides and cybutryne. Match the product name, maker, batch details and supporting technical or safety data sheets to the paint supplied. A general sales description is insufficient.

2. Record the work actually completed. Keep application dates, yard and contractor details, areas treated, invoices and application reports. Where a controlled coating is removed or sealed, retain evidence of the method and completion, the sealer specification and the surveyor’s verification.

3. Resolve gaps in the coating history. Seek records from previous owners, yards and manufacturers. Where documents do not establish compliance, the RO or VISR may require further verification, including sampling or testing. Do not treat missing information as proof that a controlled substance is absent.

Supporting guidance: MEPC.358(78), sections 4–6 and appendix II

Arrange containment and lawful disposal of paint residues, abrasive material and contaminated wash water during removal or repair. Follow the yard’s applicable environmental requirements and the IMO guidance on coating removal. Keep the relevant disposal records. Check local restrictions before any in-water cleaning or coating work. (AFS Convention article 5) (IMO AFS.3/Circ.6, 2024 removal guidance)

8. Compliance Confirmation and Follow Up

Within 30 calendar days after publication of this circular, owners or managers must send VISR’s Technical Department a compliance confirmation for each vessel. A fleet schedule may be used. Include:

a. Vessel particulars. Name, IMO or official number, GT, verified length, operating area and responsible RO, where applicable.

b. Coating evidence. Product and manufacturer, last application date, manufacturer’s compliance declaration, and any evidence of removal or sealing. Identify any cybutryne deadline or claimed exception and its supporting basis.

c. Current documentation. AFS Certificate and Record, or the owner’s declaration, as applicable. State the next planned coating renewal or docking and any outstanding survey or corrective action.

Report a prohibited application, an expired removal or sealing deadline, or a material documentation gap immediately. The 30-day reporting period is not a grace period for non-compliance. Coordinate corrective measures with VISR, the authorized RO and the relevant port or coastal authority before proceeding with affected work or operations.

ROs are requested to verify compliance within their authorization, ensure that certificates and endorsements reflect the actual system, and notify VISR of material deficiencies. Owners remain responsible for compliance and for bringing this circular to the attention of masters, managers and coating contractors.

Send to: technical@register-vu.com  |  Copy: compliance@register-vu.com
Subject: AFS compliance confirmation — [vessel name / IMO number]