Survey Matters April 2023

In this edition, learn more about careers at AMSA and maintenance plan essentials.

In this edition

Careers at AMSA

AMSA is looking for individuals who are passionate about helping us achieve our vision of safe and clean seas, saving lives. It’s important and rewarding work and you can join us to play your part.

Click here to see a list of current vacancies, including two Senior Naval Architect positions. 

You can also subscribe for AMSA job alerts by clicking here

Audits and application assessments

AMSA audits accredited marine surveyors to ensure the processes set out in the National Law–Marine Surveyors Accreditation Guidance Manual (SAGM), Marine Order 503 and the Marine Safety (Domestic Commercial Vessel) National Law Regulation 2013 (the Regulations) are followed correctly.

In December 2022, AMSA received a complaint from the owner of a 1D vessel regarding deficiencies identified during an out of water survey.

AMSA commenced an audit and requested a list of pending deficiencies from the surveyor, as well as the applicable standards and rules related to the deficiencies.

AMSA found the standards applied for the deficiencies were not applicable for the vessel as per Section 7 of Marine Order 503. The surveyor also failed to follow the relevant process for disputed deficiencies as outlined in SAGM Part 2 Chapter 2.9.4.

The surveyor was issued a counselling letter for contravention of conditions of accreditation.

Draft Instruction to Surveyors now available - 10 yearly internal inspections

AMSA has developed a draft Instruction to Surveyors (ITS) which outlines the processes and acceptable options for internal hull, fuel tank cofferdam, and foam buoyancy inspections required by SAGM Part 2 for a 10-year renewal survey.

Several surveyors have rightly asserted that under the strictest interpretation of 10-year survey requirements, DCVs (particularly smaller vessels) with sealed underdeck spaces, may require extensive and destructive works to permit inspection. This would ultimately lead to greater damage to the vessel and a lower safety outcome than leaving these spaces intact.

As part of the ITS development, AMSA welcomes any feedback from accredited marine surveyors on the form and content of the attached draft. AMSA is particularly interested in the processes that surveyors may already have in place for the inspection of sealed underdeck spaces and foam buoyancy materials, and the condition of these spaces on older vessels undergoing survey.

Any comments and feedback can be directed to, with ‘DCV-ITS feedback’ in the subject line. This will ensure that all feedback can be easily collected and collated.

Click here PDF203.32 KB to access the draft ITS.

Periodic lightship check - comparison of departure conditions is not acceptable

Recently, an accredited surveyor recommended a periodic lightship check after measuring the vessel’s departure condition and comparing this with the departure values shown in the stability book.

The surveyor concluded there had been no (0%) change in vessel lightship from this measurement and recommended the vessel’s certificate be renewed.

AMSA identified this during assessment of the application and required a lightship measurement to be conducted on the vessel.

The lightship comparison correctly identified that the vessel’s lightship displacement had, in fact, changed by almost 8 tonnes. The vessel was re-inclined, and the VCG had increased significantly.

Comparison of departure conditions is not an acceptable method to assess a vessel’s lightship displacement or determine if any modifications have occurred.

As shown by this case, a comparison of departure condition does not provide evidence that a vessel has not been modified. Whilst a vessel’s loaded displacement may remain constant, other changes may still have occurred, such as replacement of lead ballast with additional tanks, awnings, etc.

For example, in the case of the Returner, the coroner’s report states:  

 103. The AMSA/DoT investigators concluded that if the vessel’s weight (checked through the freeboard) was the sole or deciding factor used to determine whether further testing of stability was required, a false conclusion may have been reached. It appears that this is what did occur. 

Applications recommended with this kind of method may be refused by an AMSA delegate and lead to investigation by AMSA’s surveyor audit team.

Vessel repairs

AMSA recently became aware of several new vessels of a similar design displaying advanced pin hole corrosion in sections of buoyancy tube plating. The vessels were relatively new, undergoing their first renewal surveys when the corrosion was detected.

The severity of the corrosion ranged from relatively minor pitting to larger pits, which a tool could be easily passed through. The range of corrosion identified provides an excellent case study into repair practices and the accredited surveyors’ role in reporting and overseeing the repair process.

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Minor repairs

One of the vessels in question had only very minor pitting that was just beginning to show on the outer parts of the hull. The vessel owners wanted to know if a surveyor was required to review, inspect, and approve the repairs. Below are two sections of the solid buoyancy tube requiring repair.

Solid buoyancy tube requiring repair.Solid buoyancy tube requiring repair.


Guidance notice for further guidance. However, if you are asking the question, it’s probably not minor maintenance and, therefore, worth conducting an approval and inspection. There is no harm in this course of action.

Major repairs & accredited surveyor approval

A major repair that would require accredited surveyor approval is typically when the watertight integrity of the hull or a subdivision on the vessel will be affected. Examples of this could include cropping and replacing large sections of bottom plating, repair of a watertight bulkhead due to collision or other damage.

During this process, if the alterations occur that are listed in Marine Order 503 Schedule 1, an initial survey and application is required.

AMSA can generate ad hoc survey codes for repair surveys where an initial survey and application isn’t required. Email to have an ad hoc survey code issued.

Repair standards

The underlying principle is that the repair will be as strong as the original structure. If modifications are made to improve the structure, such as removal of stress concentrations, additional bracketing, or other items, so much the better.

With respect to welding of aluminium, AMSA provides guidance in DCV-ITS-008 for welder qualifications, as well as guidance on defects and repairs. Additional information can be found in WTIA Technical Note 2.

In terms of the conduct of repairs, AMSA does not have a specified repair standard, only that the repair has the same integrity as the original structure. AMSA does suggest referring to a standard to give an auditable and justifiable rationale to approved repairs.


Generally speaking, welding of pin hole/pitting in aluminium is not acceptable (as per the definition in Guidance Notice AMSA 830), however, for highly localised repairs in low-risk plating, this could be accepted. The key here is identifying the risk of the defect, the repair and if a systemic problem is present. The consequence of continued failure must also be considered, i.e. there is a lower risk in an aluminium tube (of a solid collar RHIB) than the hull bottom plating. Flooding of the watertight envelope, particularly in the case of a vessel that is not foam filled, is a comparatively higher risk for flooding.

A leak in a tube (particularly if foam filled) is not ideal but most likely won’t directly lead to the vessel taking on large amount of water and/or foundering, compared to a leak in the hull bottom plating in a vessel without buoyancy foam, which could have this outcome.

Ultimately, it is the surveyor’s judgement as to the final repair plan and their satisfaction in the completed repair. In the event of a disagreement with the vessel owner, there is the avenue to submit a disputed deficiency. Refer to SAGM Section 2.9.4 for this process. Note there is a requirement that the details of the dispute are submitted in writing to AMSA, as per SAGM Section 2.9.4 (b)(i).

The presence of corrosion in a relatively new vessel is also a reminder to check items on a vessel regardless of age rather than to assume compliance. It also shows the value of identifying trends in vessels, by type, operations, age, or any other metric.

Furthermore, if in doubt about the level of repair required or to record the results of a minor repair, please don’t hesitate to contact AMSA for guidance.

Polyurethane sealant in timber vessels

AMSA inspectors have noticed an increase in the number of timber vessels with polyurethane sealants used in the underwater plank seams instead of the usual seam putty. Inspectors have identified that these sealants have been coming away from the seams, exposing the caulking and contributing to water leaks and moisture issues on vessels.

AMSA does not recommend the use of polyurethane sealants, because they do not work well in these underwater seams and fall out over time.

AMSA encourages the following best practice recommended by experienced shipwrights:

  1. Clean out the seam thoroughly.
  2. Paint underwater primer on timber planks.
  3. Hammer oakum or cotton caulking.
  4. Prime again.
  5. Linseed putty with antifoul mixed in (for the putty worm).
  6. Prime again.
  7. Paint / antifoul.

Load line conditions of assignment

Load line certificates are issued subject to the conditions mentioned in Section 7 of Marine Order 507.

Marine order 507 Section 7 (1) (a) states:

the master must ensure that the conditions of assignment of load lines in the approved form are kept on board the vessel or, where it is impractical to keep the documents on board due to the structure of the vessel, made available on request of a marine safety inspector or the National Regulator.

The load line conditions of assignment must be met before the freeboard is assigned to a ship and a load line certificate is issued.

The conditions of assignment are also referenced during periodic load line surveys to determine if the vessel has been modified and whether guardrails, freeing ports, means of access for the crew, and appliances for the protection of openings are maintained effectively.

AMSA understands for some vessels built and certified before 2013, initial load line survey reports may not be available in records or on-board vessels.

For such vessels, details regarding freeing ports, guardrails, and means of protection and closure of openings (such as hatchways, doorways, ventilation, air pipes, etc) must be recorded during the load line renewal survey.

Accredited surveyors can submit the AMSA 555 Conditions of assignment report together with the AMSA 139 Load line survey report to support the renewal of a load line certificate.

Minor fixes can save major costs later

Updated guidance and templates are now available to help small domestic commercial vessel owners and operators develop and implement a maintenance plan for their operation.

An analysis of 117 reported marine incidents involving DCVs since 2020 found that maintenance failures were a factor in almost one-third. Common deficiencies identified by AMSA relate to the condition of safety equipment and validity of certification associated with these vessel operations, including overdue periodic surveys.

There is more to maintenance than just main engine servicing.

Developing and implementing a maintenance plan, and logging work undertaken, may help prevent a more serious underlying issue from turning into a breakdown, which puts a vessel out of the water and people out of business.

Small owners and operators are encouraged to visit AMSA’s maintenance plan essentials, available on our website. This guidance is designed specifically to help small operations which don’t necessarily have the same shoreside support as medium and larger DCV operations.

Last updated: 27 April 2023