What the 2025 Numbers Actually Say
Three consecutive years of rising detention rates tell you the enforcement environment is tightening, not loosening. But the operational lesson is in the distribution: the same categories recur year after year. Detention is rarely a surprise — it is usually the visible consequence of something that was already true about the ship's management before the inspector arrived.
The Deficiency Categories That Dominate
From the Paris MoU Annual Report for 2025, the leading recorded deficiency categories were:
| Category | Share of all deficiencies | What it usually means in practice |
|---|---|---|
| Safety Management System (ISM Code) | ~4.5% (2,322 instances) | Procedures not followed, records not kept, corrective actions not closed — a systemic finding |
| Fire doors & openings | ~3.1% (1,609) | Doors wedged open, damaged seals, defective closing devices — a classic detainable safety item |
| Seafarers' Employment Agreements | ~1.3% (664) | MLC documentation gaps, terms not matching, missing signatures |
| Engine room cleanliness | ~1.3% (654) | Oil accumulation and leaks — read as both a fire risk and a management-standard indicator |
| General electrical installations | ~1.3% (646) | Temporary repairs, exposed wiring, defective lighting |
Fire safety deserves particular attention. Fire doors are cheap to maintain and expensive to fail on — and unlike many findings, a defective fire door is immediately visible, objectively assessable and hard to argue with. It is one of the highest-return items on any pre-arrival check.
Why ISM Findings Cause Detentions
An ISM deficiency is qualitatively different from a broken pump. A broken pump is a fault. An ISM finding says the system that should have caught the fault is not working — which puts every other system on the ship in question.
Two routes lead there:
- A direct finding — procedures absent, not followed, or records missing.
- Accumulation. This is the one operators underestimate: a collection of individually minor, non-detainable deficiencies can together demonstrate that the safety management system is ineffective — and that conclusion is detainable.
This is why "we only had small findings" is not a safe position. Five trivial deficiencies across five different systems is not five small problems; to an experienced PSCO it is one large one. Managing the count of findings matters as much as managing their individual severity.
It also explains why maintenance discipline shows up in vetting and PSC outcomes alike — overdue critical jobs and thin defect history are exactly the evidence that supports an accumulation finding. See our PMS guide for the maintenance-evidence side.
How PSC Decides Which Ships to Inspect
Modern regimes do not inspect at random. Under the Paris MoU's risk-based approach, every ship carries a Ship Risk Profile:
| Profile | Inspection window | Practical consequence |
|---|---|---|
| Low Risk Ship (LRS) | 24–36 months | Inspected rarely; a substantial commercial and operational advantage |
| Standard Risk Ship (SRS) | 10–12 months | The default position for most tonnage |
| High Risk Ship (HRS) | 5–6 months | Frequent, more expansive inspections — a compounding burden |
The profile is built from factors including ship type and age, flag State performance, recognised organisation performance, company performance, and the ship's own deficiency and detention history. Several of those you cannot change quickly. Company performance and inspection history you can.
Priority I versus Priority II
- Priority II — the inspection window has opened; the ship may be selected.
- Priority I — the window has passed, or an overriding factor has been recorded; the ship will be selected.
The strategic point: a clean history does not merely avoid one detention. It moves the ship toward a lower-risk profile, which means fewer inspections, which means fewer opportunities to be found wanting. Good performance compounds — and so does bad.
What Makes a Deficiency "Detainable"
A deficiency becomes detainable when the officer judges the ship unsafe to proceed to sea — a danger to the ship, those on board, or the environment. In practice the recurring detainable themes are:
- Fire safety — doors, dampers, detection, fixed systems, means of escape.
- Life-saving appliances — lifeboats, davits, release gear, liferaft servicing.
- Safety of navigation — defective equipment, charts and publications not current.
- Emergency systems — emergency generator, fire pump, steering gear.
- ISM — systemic failure, directly or by accumulation.
- MARPOL — including oil record-keeping; see our Oil Record Book guide.
- MLC — employment agreements, wages, food and accommodation, hours of rest.
A Pre-Arrival Self-Check That Works
Aim the check at where findings actually occur, not at everything equally. Working through this list is a genuine hour or two, not a tick sheet:
- Fire doors and closing devices — every one, operated, seals intact, nothing wedged.
- Escape routes — unobstructed, signage and emergency lighting working.
- Engine room cleanliness — no oil accumulation, leaks traced and stopped, bilges clean.
- Electrical — no temporary repairs, no exposed wiring, enclosures secured.
- LSA — lifeboat and rescue boat operable, release gear serviced, liferaft certificates current.
- Emergency equipment — emergency generator, emergency fire pump and steering gear tested and recorded.
- Certificates — all valid, endorsements current, nothing expiring in the next port rotation.
- Records — Oil Record Book, garbage, rest hours, drills — contemporaneous, complete, signed.
- Overdue PMS jobs — especially anything flagged critical.
- Open corrective actions — from internal audits, previous PSC and vetting; closed with evidence.
- Crew familiarisation — can the duty crew actually operate the emergency equipment, on request?
Item 11 is where preparation most often fails. Modern inspectors ask crew to demonstrate, not just to produce paperwork — the same shift that SIRE 2.0 formalised for tanker vetting. Equipment that works, operated by someone who cannot work it, is still a finding.
Improving Your Ship Risk Profile Over Time
- Kill repeat findings. Nothing damages a profile like the same deficiency twice. Close on root cause, not on symptom.
- Reduce the deficiency count, not just severity. Accumulation is a detention route in its own right.
- Make the SMS operational. If procedures do not match what the ship actually does, fix the procedure — drift is what an ISM finding detects.
- Keep evidence retrievable. A finding you cannot disprove in the moment becomes a finding on the record.
- Track fleet-wide patterns. If one deficiency category recurs across ships, it is a management issue, not a ship issue.
- Treat company performance as an asset. It feeds the profile of every vessel you operate — improvements compound across the fleet.
See the findings before the inspector does
Volaxin connects maintenance, defects, corrective actions, certificates and statutory records on one dataset — so overdue criticals, open CAPAs and expiring certificates are visible fleet-wide before arrival, not after detention. Book a demo.
Request a DemoFrequently Asked Questions
What is a detainable deficiency?
A finding serious enough that the ship is judged unsafe to proceed to sea. An accumulation of minor findings demonstrating an ineffective safety management system can also be detainable.
What deficiencies most often lead to detention?
Per the Paris MoU 2025 report: ISM/safety management (~4.5% of all deficiencies), fire doors and openings, seafarers' employment agreements, engine room cleanliness and general electrical installations.
How does PSC choose which ships to inspect?
By risk-based targeting. The Ship Risk Profile (Low/Standard/High) is built from ship type and age, flag, RO and company performance and inspection history, and sets windows of 24–36, 10–12 or 5–6 months respectively.
What is Priority I vs Priority II?
Priority II — window open, may be inspected. Priority I — window passed or an overriding factor recorded; will be inspected.
How do we reduce detention risk?
Eliminate repeat findings, reduce total deficiency count, keep the SMS genuinely operational, close corrective actions on root cause, and run a targeted pre-arrival self-check.
Scope & Sources
Figures cited are from publicly reported summaries of the Paris MoU Annual Report for 2025. Statistics, categories and procedures change annually and differ between MoU regions (Paris, Tokyo, USCG and others). Always verify against the current Paris MoU publications and the requirements of the specific regime and port. Nothing here constitutes legal advice.