The Hong Kong Convention does not apply only to newly built vessels. It applies to all ships of 500 GT and above, regardless of when they were built. For a vessel delivered in the 1990s or early 2000s, the original builder’s records may be incomplete, out of date, or simply unavailable — and yet the obligation to carry a verified IHM and a valid ICIHM is the same.
This is one of the more practically difficult compliance challenges for older superyachts, and it starts with understanding what an initial survey on an existing vessel actually involves.
What the Convention requires for existing vessels
The IHM Implementation Certificate (ICIHM) is issued following an initial survey confirming that the IHM is complete, accurate, and properly documented. For a vessel that has never undergone this survey — because the requirement did not exist when it was built — the initial survey establishes the IHM from scratch.
The IMO guidelines for IHM implementation (MEPC.269(68)) describe the approach for existing ships. The process for an older vessel without builder documentation differs from a new build, and involves a combination of document review, visual inspection, and, where necessary, sampling.
Your class society will advise on their specific survey procedures. What follows is the general framework from the IMO guidelines.
Why older vessels present specific challenges
The Annex I controlled substances under the HKC — those required to be inventoried in Part I — include materials that were in common use during earlier construction periods:
- Asbestos (Table A) — used extensively in pipe lagging, insulation, and fire protection materials on vessels built before the industry-wide shift away from asbestos in the 1980s and 1990s
- Polychlorinated biphenyls (PCBs) (Table A) — found in some transformers, capacitors, and hydraulic fluids in older electrical installations
- Organotin compounds including tributyltin (TBT) (Table A) — used in antifouling paints; banned internationally from January 2008 under the AFS Convention but may still be present in older coatings on hull surfaces
- Ozone-depleting substances (Table A) — older refrigeration and air conditioning systems may use refrigerants such as R-11, R-12, R-22, or HCFC blends that are ODS
The presence of any of these substances does not automatically create a compliance problem — it creates an inventory obligation. The IHM records what is there, where it is, and in what condition. The ICIHM certifies that the record is accurate.
The initial survey process for an existing vessel
For an older vessel going through an initial IHM survey, the class society surveyor will typically work through several stages. The exact procedures are set by your class society and flag state, but the IMO guidelines describe the following general approach:
Document review. Any records that do exist — construction drawings, equipment specifications, maintenance records, previous surveys — are reviewed for information about materials installed. Even incomplete records can help scope the physical inspection.
Visual inspection. A systematic inspection of the vessel’s spaces and equipment identifies materials that may be Annex I substances. The surveyor inspects representative samples in areas where hazardous materials are likely to be present — machinery spaces, accommodation insulation, pipework systems, electrical installations.
Sampling. Where visual inspection cannot determine whether a material contains a controlled substance, samples may be taken for laboratory analysis. This is most common for insulation materials where the presence or absence of asbestos cannot be confirmed visually.
Part I compilation. Based on the inspection and analysis results, Part I is compiled to record the identified hazardous materials — type, location, approximate quantity, and condition. Materials confirmed as absent need not be listed.
When documentation simply does not exist
For some older vessels, particularly those that have changed ownership multiple times, original builder documentation may not be available at all. The IMO guidelines address this: where documentary evidence is unavailable, the initial survey relies on physical inspection and sampling to establish the IHM.
This is not a barrier to compliance — it is the defined path. An IHM established through inspection and sampling is as valid as one built from original builder records. The key is that the survey is conducted by a recognised authority (your class society or flag state administration), and the findings are properly documented.
What to do before commissioning an initial survey
Before engaging your class society for an initial survey, it is worth assembling everything that does exist:
- Original build specification documents and equipment lists
- Previous class surveys — any survey records that reference structural or equipment condition
- Maintenance records that document material changes or replacements
- Any existing hazardous materials assessments, even informal ones
- Records of refits, conversions, or modifications since original delivery
None of these need to be complete. Even partial information reduces the scope of physical inspection required and can help locate materials that might otherwise be missed.
After the initial survey
Once the initial survey is complete and Part I is verified, the ICIHM is issued. From that point, the vessel is on the standard HKC survey cycle — renewal at intervals not exceeding five years, with Part I maintained and updated as material changes occur.
The most important thing to establish at the initial survey stage is the change recording discipline that will sustain the IHM going forward. An IHM that is accurate today but never updated will fail at renewal. The initial survey is the baseline; maintenance is the ongoing obligation.
For the full picture of what an IHM requires and how to keep it current, see the complete guide to IHM for superyachts.
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