Offshore support vessels are the only sector in shipping where assurance is effectively the product. A PSV or AHTS does not merely have to be maintained — it has to be demonstrably maintained, to a charterer's satisfaction, before it can earn, and the demonstration is a recurring, third-party-witnessed, chargeable event. IMCA M 103 states that all DP vessels should be subjected to annual testing of the DP system to demonstrate that the vessel remains fit for purpose for DP operations, with the annual trials programme based on the vessel's DP FMEA proving trials, covering a period of more than one year and repeated after five years. Class and IMO requirements sit alongside that, calling for an initial survey, an annual survey covering all important systems and components, and periodical testing at intervals not exceeding five years requiring a complete test of all systems and components. Then there is eCMID, the charterer's own audit, lifting gear certification, and since 1 January 2026 a new statutory regime for anchor handling winches. Buried inside IMCA M 190 is a provision most operators underuse: planned maintenance or survey records may be accepted in lieu of specific annual test results. Your maintenance record can reduce your trials scope. Start a free trial of Marine Inspection and make it good enough to count.
01
DP assurance
FMEA proving trials, annual trials programmes conforming to IMCA M 190 methodology, and five-yearly periodic trials, attended by an independent accredited practitioner.
02
Class and statutory
Initial survey, annual survey covering all important systems and components, and periodical testing at intervals not exceeding five years requiring a complete test of all systems and components.
03
eCMID and charterer audit
Supply vessels and offshore units can adhere to the inspection protocol of the IMCA Common Marine Inspection Document, now carried out through the electronic eCMID tool and issued on a periodic basis.
04
Lifting and winch certification
Cranes, winches and loose gear, including anchor handling winches brought under SOLAS Regulation II-1/3-13 by MSC.532(107) with effect from 1 January 2026.
None of these share paperwork, all of them read the same equipment, and every one of them costs vessel time. The maintenance record is the only asset that can serve all four — and under IMCA M 190 it can substitute for part of one of them.
DP Assurance Is a Five-Year Programme, Not an Annual Event
The most common structural misunderstanding in OSV assurance is treating DP trials as something that happens once a year. The guidance describes something rather different. Book a Marine Inspection demo and see the whole cycle scheduled rather than the next date only.
Baseline
FMEA and proving trials
A DP FMEA is a desktop study requiring complementary sea trials to demonstrate its effectiveness. FMEA proving trials are a class requirement for DP Class 2 and Class 3 vessels, and they validate that failure responses and redundancy logic behave as the analysis predicts. Everything downstream is built on this document.
Years 1-5
Five annual trials programmes
The annual trials programme is based on the vessel's FMEA proving trials and covers a period of more than one year, with the FMEA proving trials date generally taken as the anniversary. Five DP annual trials are carried out across the five-year period, each conforming to the methodology set out in IMCA M 190.
Year 5
Five-yearly periodic trials
The programme is repeated after five years. Five-yearly periodical trials extend the annual trials and can include tests from the initial programme, with class and IMO requirements calling for a complete test of all systems and components at intervals not exceeding five years.
Year 6
Annual trials resume
The cycle restarts. Which means DP assurance is a continuously running programme with items falling due across a multi-year horizon, not a date in a calendar — and scheduling it as a single annual event is how vessels arrive at a five-yearly with more scope than anyone budgeted.
The Provision Most Operators Underuse
This is the commercially significant paragraph in IMCA M 190, and it converts maintenance record quality directly into vessel time and trials cost. Sign up for Marine Inspection and build records capable of carrying that weight.
What the guidance permits
IMCA M 190 details that planned maintenance or survey records may be accepted in lieu of specific annual test results. Where the maintenance system already demonstrates that a component has been tested, examined or proven, that evidence can stand in place of running the test again during annual trials.
It is a small paragraph with disproportionate consequences, because it establishes the maintenance record as an accepted form of assurance evidence rather than as internal documentation that happens to exist alongside the trials programme.
Most operators either do not know the provision exists or hold records in a form that could never satisfy it. Both outcomes have the same effect: tests get performed during a trials window that could have been evidenced from work already completed and already paid for.
The conditions are specific
Very specific conditions apply, including the completion of a test sheet confirming what evidence exists to support the test. This is not a general substitution of paperwork for testing, and it is not available for everything. Treat it as a defined mechanism with defined evidence requirements rather than as a shortcut.
Why it matters commercially
Trials time is vessel time. Every test that can be evidenced from existing maintenance records rather than performed again during a trials window is time the vessel is not off-hire, and cost not incurred for an attending practitioner. A maintenance record good enough to be accepted is therefore a directly monetisable asset rather than an administrative overhead.
What makes a record good enough
Attribution to a named competent person, a date, the specific test or examination performed, the acceptance criterion applied and the measured result — held against the individual component rather than the system. A completion tick against a job title satisfies nobody; a recorded value against a stated criterion, signed, might.
IMCA M 190
Planned Maintenance Records May Be Accepted in Lieu of Annual Test Results
Component-level records with named attribution, stated acceptance criteria and measured results, linked to the FMEA failure modes they evidence and exportable as a trials evidence pack. The better the record, the smaller the trials scope, and the less vessel time an assurance cycle consumes.
Rolling Tests Are Not a Sample
Rolling test programmes are widely misunderstood as testing a percentage of the programme each year. The guidance is explicit that they are something more disciplined than that, and the discipline has a documentation requirement attached. Schedule a walkthrough and see FMEA failure modes linked to the maintenance evidence that supports them.
What rolling tests do
A rolling programme contributes to effective management of the failure modes and effects analysis and makes better use of the time available for DP system tests, by more effectively identifying items which do not need to be tested every year, or whose reliability can be demonstrated by other means.
What they are not
They are not simply a percentage sample of the overall DP annual trials programme. Selecting a proportion of tests at random and deferring the rest does not constitute a rolling programme and will not survive scrutiny by an accredited practitioner or a charterer's auditor.
The precondition
In every case the failure modes associated with these tests must be understood and must already have been verified and validated within the FMEA proving trials programme. The FMEA is the authority for what can be rolled, which is why its currency matters as much as its existence.
Where it applies well
Examples include tests on non-critical redundancy and multiple failure modes of the same system — a thruster variable speed drive with numerous points of failure, or individual power system tests that are automatically covered by wider group redundancy testing.
The systems consequence
A rolling programme requires three things held together: the FMEA and its validated failure modes, the trials programme built from it, and the maintenance evidence supporting deferred items. Where those live in three separate places — a consultant's PDF, a spreadsheet and a maintenance database — the programme cannot be defended and the tests get run again.
The Assurance Calendar
Below is what an OSV operator has to track and where each item usually slips. Start a free trial and load one vessel's assurance calendar during the evaluation.
Table 1: What an OSV Has to Keep Current
| Item | Cycle | What It Requires | Where It Slips |
|---|---|---|---|
| DP FMEA | Reviewed on change, revalidated within the five-year cycle | Currency against the vessel's actual equipment after conversions, upgrades or a class change | An FMEA written at newbuild describing a thruster configuration that has since changed |
| FMEA proving trials | At baseline and on significant modification | Sea trials demonstrating that failure responses and redundancy logic behave as analysed | Held by the consultant who performed them rather than by the vessel |
| DP annual trials | Five across the five-year period | A programme conforming to IMCA M 190 methodology, attended by an accredited practitioner | Scheduled as a date rather than as a programme spanning more than a year |
| Five-yearly periodic trials | Not exceeding five years | A complete test of all systems and components, extending the annual programme | Scope discovered late because deferred items were never tracked |
| ASOG, CAM and TAM | Updated regularly to reflect changes | Activity Specific Operating Guidance, Critical Activity Mode and Task Appropriate Mode, developed with stakeholders | Written once and not updated when the vessel or its DP system changed |
| DP capability plots | Available to the operator | Current plots reflecting the vessel's actual configuration | Superseded by equipment changes and never regenerated |
| eCMID | Periodic | Inspection under the IMCA Common Marine Inspection Document protocol via the electronic tool | Findings closed operationally with nothing recorded against the asset |
| Lifting appliances | Per certification regime | Certification, thorough examination and test records per appliance and per item of loose gear | Loose gear grouped rather than held individually with SWL and certificate |
| Anchor handling winches | Certification at first renewal survey after 1 January 2026 | Requirements under SOLAS II-1/3-13 as amended by MSC.532(107), with IMO guidance in MSC.1/Circ.1662 | Nobody established whether the vessel's winches fall within the definition |
| Key DP personnel | Continuous | Training and experience consistent with IMO and IMCA guidance, held per individual | Certification tracked by the manning agent and not visible to the vessel |
FMEA, trials programme, deferred items and supporting maintenance evidence in one place — because a rolling programme cannot be defended from three.
Lifting Gear and the January 2026 Winch Regime
Offshore support vessels carry more certificated load-bearing equipment than almost anything else afloat, and a new statutory layer landed at the start of 2026 that reaches AHTS tonnage directly. Book a walkthrough and see gear held per item with certificates, examinations and discard thresholds.
The new obligation
Anchor handling winches were brought under direct regulation by SOLAS Regulation II-1/3-13 as amended by IMO Resolution MSC.532(107), in force from 1 January 2026 and supplemented by the IMO Guidelines for Anchor Handling Winches in MSC.1/Circ.1662.
They are defined as winches used for deploying, recovering and repositioning anchors and mooring lines in subsea operations, typically installed on dedicated anchor handling vessels and offshore support ships. For an AHTS operator this is the definitional home of the requirement rather than an edge case to be assessed.
The requirements reach beyond certification into operation. The winch must be included in the onboard maintenance programme, maintenance and operational manuals must be available or reconstructed in accordance with the guidelines where they are missing, and personnel must be properly qualified and familiarised with the equipment.
Certification
Required before use, covering plan appraisal, material verification, fabrication survey and testing. For existing equipment, certification falls due at the first renewal survey after 1 January 2026, with existing valid certificates under other international instruments remaining acceptable.
Testing
Commissioning tests for new installations cover function at light load, overload, emergency release, brake holding capacity and bollard pull where designed for towing. The five-yearly test should be witnessed by the Administration or a recognised organisation, and thorough examination is conducted at annual surveys, after repairs and with load testing.
The records gap
Unlike lifting appliances, there is no prescribed register booklet for anchor handling winches, yet IMO guidance still requires thorough examination and testing records to be legible, complete and authenticated by a competent person. The obligation exists without the standard form that would normally carry it, so the operator's own system has to fill that gap.
The Charterer Audit Is the One That Stops the Contract
Class can issue a condition. Flag can raise a deficiency. A charterer can decline the vessel, and that is the outcome with immediate revenue consequences. Start a free trial and hold audit findings as tracked corrective actions rather than as a report filed after the visit.
eCMID as the common language
Supply vessels and offshore units can adhere to the inspection protocol given by the IMCA Common Marine Inspection Document, carried out through the electronic eCMID tool and issued periodically. Its value is that it gives operator and charterer a shared framework rather than a bespoke questionnaire per client.
DP assurance is client assurance
The assurance of the DP annual trials programme is a key part of any client's vessel assurance activity. That means your trials programme is read by people deciding whether to hire the vessel, not only by people deciding whether to certify it, and its quality is assessed alongside the technical outcome.
Independence is defined
IMCA M 190 defines the relevant independent individual as sufficiently qualified and experienced and removed from day-to-day operational control of the vessel. Practitioner accreditation runs through the IMCA scheme, with revalidation on a three-yearly cycle and evidence of ongoing DP practitioner experience required.
Findings compound across clients
An open finding from one charterer's audit is visible or discoverable at the next. Closing findings promptly with evidence attached is therefore not administrative housekeeping — it is the difference between arriving at the next audit with a clean position or with a history someone else recorded on your behalf.
The pattern worth noticing
Every regime described on this page reads the same equipment and asks a version of the same question: has this been tested, by whom, against what criterion, and what was the result. Four separate evidence packs get assembled from one underlying reality, usually four separate times, by the same overworked chief engineer. The consolidation opportunity is not marginal — it is most of the administrative cost of running an OSV.
Evaluating a Platform for an OSV Fleet
Generic marine maintenance software has no concept of DP assurance, trials programmes or FMEA linkage. These questions establish whether a platform can carry the sector's actual burden. Schedule a demo with a DP superintendent and a chief engineer present.
Table 2: Buyer Questions Specific to OSV Operators
| Area | The Question | A Real Answer | What Should Worry You |
|---|---|---|---|
| Trials evidence pack | Can we export maintenance evidence formatted to support a test sheet? | Component-level records with attribution, criterion and result, exportable | Completion ticks with no measured value or named person |
| FMEA linkage | Can maintenance items be linked to the failure modes they evidence? | A relationship between FMEA items and the jobs supporting them | The FMEA held as a PDF attachment with no structural link |
| Multi-year scheduling | Does the system handle a programme spanning more than one year? | Items scheduled across a five-year horizon with deferred items visible | An annual calendar with no multi-year view |
| Deferred item tracking | Can we see what was rolled forward and why, at any point in the cycle? | A deferral record with justification and target date | Deferrals held in the practitioner's report only |
| Loose gear | Is every shackle, sling and item of loose gear an individual asset? | Per-item SWL, certificate, examination date and discard threshold | Loose gear as a single category with one certificate reference |
| Winch scope | Does the system distinguish anchor handling winches from other winches? | Scope status per unit with the applicable certification and test regime | Winches modelled generically with no regulatory attribute |
| Audit findings | Does an eCMID or charterer finding become a tracked corrective action? | One-step conversion with owner, deadline and closure evidence | Findings held in the inspection report and actioned by email |
| Offline capture | Can records be captured on deck and in machinery spaces offshore? | Airplane mode demonstration with photographs and a clean sync | Reliance on offshore connectivity being adequate |
| Reference | Which OSV operators of our vessel type use this today? | A named, contactable reference running comparable DP tonnage | Cargo fleet references offered as equivalent experience |
2026 OFFSHORE ASSURANCE REALITY
IMCA guidance is guidance, not law. IMCA publications state expressly that the information is given for guidance only and endeavours to reflect best industry practice, with no legal liability attaching. It nonetheless functions as the de facto standard because charterers apply it, so treat it as commercially binding while recognising its formal status. Class requirements vary in detail. All major classification societies and the IMO have requirements for annual surveys or tests of the DP system, but guidance on the specific content of those surveys varies, and some societies may accept a limited number of functional tests in particular circumstances. Confirm your own society's position rather than assuming uniformity. The in-lieu provision has conditions. Planned maintenance or survey records may be accepted in place of specific annual test results, but very specific conditions apply including completion of a test sheet confirming what evidence exists. Agree the approach with your practitioner in advance rather than presenting records at the trial. The winch requirements are new and still settling. Some details have been the subject of continuing discussion between societies and administrations; confirm your society's current position.
Frequently Asked Questions
How often are DP trials required?
More continuously than the word annual suggests. IMCA M 103 states that all DP vessels should be subjected to annual testing of the DP system to demonstrate the vessel remains fit for purpose for DP operations, with the annual trials programme based on the vessel's FMEA proving trials, covering a period of more than one year and repeated after five years. In practice five DP annual trials are carried out across the five-year period, with the FMEA proving trials date generally taken as the anniversary, and the programme resuming in year six. Class and IMO requirements sit alongside this, calling for an annual survey covering all important systems and components and periodical testing at intervals not exceeding five years requiring a complete test.
Can planned maintenance records replace DP annual tests?
Partially, and under defined conditions. IMCA M 190 details that planned maintenance or survey records may be accepted in lieu of specific annual test results, with very specific conditions applying including completion of a test sheet confirming what evidence exists to support the test. This is not a general substitution of documentation for testing, and it is not available across the board. What it does mean is that a maintenance record carrying named attribution, the specific examination performed, the acceptance criterion and the measured result — held against the individual component — has direct commercial value, because every test it supports is trials time the vessel does not spend off-hire.
What exactly is a rolling test programme?
A method of managing the failure modes and effects analysis that makes better use of available test time by identifying items which do not need testing every year, or whose reliability can be demonstrated by other means. Critically, it is not simply a percentage sample of the overall annual trials programme. In every case the failure modes associated with rolled tests must be understood and must already have been verified and validated within the FMEA proving trials programme. Typical candidates include non-critical redundancy and multiple failure modes of the same system, such as a thruster variable speed drive with numerous failure points, or individual power system tests automatically covered by wider group redundancy testing.
Who is qualified to conduct DP annual trials?
The relevant guidance frames this in terms of independence and demonstrated competence. IMCA M 190 defines the individual as sufficiently qualified and experienced and removed from day-to-day operational control of the vessel. Expected qualifications for those preparing an annual trials programme include a qualified engineer holding STCW III/2 chief engineer certification or an electrical engineering degree or equivalent, or a qualified mariner holding STCW II/2 master certification, together with experience as part of a team producing at least one DP FMEA for a similar vessel and knowledge of the vessel's operational function and interfaces. Practitioner accreditation runs through the IMCA scheme with revalidation on a three-yearly cycle.
Do the new anchor handling winch requirements apply to our AHTS?
Very probably, since anchor handling vessels are the definitional home of the requirement. SOLAS Regulation II-1/3-13 as amended by MSC.532(107) entered force on 1 January 2026, supplemented by IMO guidance in MSC.1/Circ.1662, and applies to winches used for deploying, recovering and repositioning anchors and mooring lines in subsea operations — typically installed on dedicated anchor handling vessels and offshore support ships. Certification for existing equipment falls due at the first renewal survey after 1 January 2026. Note that no prescribed register booklet exists, yet records must still be legible, complete and authenticated by a competent person, so your own system has to carry that burden.
How should ASOG, CAM and TAM be managed?
As living documents rather than as a one-time deliverable. Activity Specific Operating Guidance is typically developed by the owner or operator in consultation with all stakeholders and updated regularly to reflect changes in the vessel, its DP system and its operations, setting out equipment performance limits that must be met, operational procedures that must be followed and contingency plans that must be in place. Critical Activity Mode, formerly known as Safest Mode of Operation, and Task Appropriate Mode sit alongside it. Having an FMEA supports development of the ASOG, and guidance recommends developing them even for equipment class 1 vessels where they are not strictly required.
PSV, AHTS and offshore construction
A Record Good Enough to Reduce Your Trials Scope
Component-level maintenance evidence with named attribution, stated acceptance criteria and measured results, linked to the FMEA failure modes it supports and exportable as a trials evidence pack. A five-year assurance horizon with deferred items visible. Loose gear and lifting appliances held per item. Anchor handling winch certification tracked against the 2026 regime. eCMID and charterer findings converted into assigned corrective actions with closure evidence — captured offline, on deck, by the people doing the work.
