Operations · 5 min read

Port State detention: the top deficiency areas by MoU, and how to stay off the list

Fire safety leads both the Paris and Tokyo MoU tables. What the 2024 figures say, which items detain ships, and a pre-arrival routine that works.

The Naavra operations desk · 2026-09-24 · 1,122 words · 5 min read

A Port State detention is rarely a surprise to the people who work on the ship. The fire damper that does not close, the lifeboat release gear overdue for service, the air pipe head with a stuck float: somebody on board usually knew. What turns a known defect into a detention is timing. The inspector arrives before the fix.

The regional Port State control agreements publish what their inspectors find, and the pattern is stable year after year. This article reads the 2024 annual reports of the two largest regimes, the Paris MoU (Europe and the North Atlantic) and the Tokyo MOU (Asia-Pacific), sets out what detains ships, and turns that into a pre-arrival routine.

How a ship is picked, and why it matters

Both regimes target ships by risk. Under the Paris MoU's inspection regime every ship has a risk profile, high, standard or low, built from its type, age, flag performance, the performance of its recognised organisation, the ISM company's record, and its own deficiency and detention history. The profile sets how often she is due: roughly every 5–6 months for a high-risk ship, 10–12 months for standard risk and 24–36 months for low risk. The Tokyo MOU runs its own risk-based targeting on the same principle.

Two things follow. A detention does not only cost the days it lasts; it worsens the ship's profile and the company's, and brings the next inspection closer. And the company's performance counts across the fleet, so one badly run ship raises the inspection rate of the others.

What inspectors find: Tokyo MOU, 2024

The Tokyo MOU carried out 32,054 inspections in 2024, involving 18,655 individual ships, and recorded 77,526 deficiencies.

Fire safety, life-saving appliances, working and living conditions and safety of navigation together made up 54% of all deficiencies. The report also notes that a joint concentrated inspection campaign on crew wages and seafarer employment agreements under MLC, 2006 pushed up deficiencies on conditions of employment and on health protection and medical care compared with the year before.

What actually detains ships

A deficiency is recorded; a detainable deficiency stops the ship. The Tokyo MOU publishes the items most often recorded as grounds for detention.

Read the list as a to-do list. Air pipes and ventilators are watertight integrity. Fixed fire-extinguishing systems, fire pumps and structural fire protection are fire safety. Lifeboats are life-saving appliances. And two of the top five are ISM: the inspector concluded that the safety management system was not working, usually because the other defects showed it.

What inspectors find: Paris MoU, 2024

The Paris MoU's 2024 detention rate rose to 4.03%, from 3.81% in 2023 (it was 4.25% in 2022). Fire safety was again the largest area at 17.2% of deficiencies, followed by structural and electrical items under SOLAS Chapter II-1 at 11.3%, and health protection, medical care and welfare under MLC Title IV at 10.4%. ISM Code deficiencies were 4.6%. As single items, fire doors accounted for 3.2% and seafarers' employment agreements for 1.5%. Fifteen ships were refused access in 2024.

The two regimes side by side

The regimes classify deficiencies slightly differently, so shares are not directly comparable. The message is the same in both: fire safety first, then life-saving appliances, structure and watertightness, labour conditions and the ISM system behind them.

Why these areas, every year

These are not random. They are the systems that are used rarely, degrade quietly and are easy for an inspector to test in ten minutes:

• Fire dampers, fire doors and fixed systems sit idle for months. A damper that is not exercised seizes; a door with a wedge becomes a door that does not self-close.
• Lifeboats and release gear depend on servicing intervals and on crew familiarity. The inspector asks for a drill and watches.
• Air pipes and ventilator closures corrode inside where nobody looks until a float sticks.
• Labour conditions are paperwork an inspector can compare: the employment agreement, the wage account, the rest-hour record.
• ISM is the inspector's conclusion when several of the above appear together.

A pre-arrival routine that works

If a deficiency is found

Fix what can be fixed before the ship sails, with evidence. For anything that cannot, agree a rectification plan with the inspector and the recognised organisation, and close it on the date agreed. A deficiency left open to the next port is a gift to the next inspector.

What to do Monday

• List every ship's last inspection date and result in each regime it trades in.
• Check each ship's likely Paris MoU risk profile, and the company's performance, for the next 12 months.
• Add fire dampers, fire doors, fixed systems and air pipe heads to a monthly on-board test, with photos.
• Clear every overdue fire-safety and life-saving maintenance job in the planned maintenance system.
• Review employment agreements and wage accounts on one ship per week.
• After any deficiency, fleet-check the same item on sister ships within 30 days.

Questions and answers

Topics

This article explains; it is not legal or regulatory advice. Check the instrument in force for your ship.