Insights · Compliance · Worst flags by detention
Not every flag is treated equally at the quayside. The Paris MoU ranks flag states into white, grey and black bands by their inspection record — and a ship's band decides how hard it gets checked. Here is where the 2024 lists landed.
A flag state is supposed to police its own ships. Many do not, which is why a second line of defence exists: port-state control (PSC), under which the country a ship visits inspects it regardless of whose flag it flies. In Europe and the North Atlantic this is run through the Paris Memorandum of Understanding, and once a year the Paris MoU publishes the figures that tell you which flags it trusts and which it watches.
The headline number for 2024 is the detention rate of 4.03% — the share of inspections that found deficiencies serious enough to stop the ship sailing until they were fixed. That is up from 3.81% in 2023, continuing a stubbornly high run since the pandemic. The figure and the performance lists below come from the Paris MoU 2024 Annual Report, published on 30 June 2025.
The Paris MoU sorts flag states into three bands based on their inspection and detention record over a rolling three-year window:
The band feeds directly into the inspection regime, so a flag's reputation is not abstract — it changes how a specific ship is treated the moment it ties up. This is the whole point of the system, and why which flag a ship flies is a live compliance signal rather than a piece of trivia.
| Band | Flag states (2024) |
|---|---|
| White list — best | France (#1) |
| Black list — very high risk | Cameroon (bottom), Tanzania, Moldova, Vietnam |
France topped the white list as the best-performing flag — a useful corrective to the assumption that a national flag is automatically a burden; a well-run register is an asset to the ships under it. At the other end, Cameroon sat at the bottom of the ranking, sharing the very-high-risk black-list band with Tanzania, Moldova and Vietnam. A vessel reflagging to one of these registries is, in effect, signing up for harder inspections everywhere it calls in the Paris MoU region.
A flag's place on the white, grey or black list is not a label a ship can leave behind by repainting — it follows the registry, and the registry follows the hull. Paris MoU 2024 Annual Report, 30 June 2025
Black-list flags overlap heavily with the patterns seen elsewhere in maritime risk. The same obscure registries that perform worst on detention frequently turn up flagging old hulls in the shadow fleet, because the qualities that make a flag cheap and lax — light oversight, fast registration, no questions asked — are exactly what an operator trying to dodge scrutiny is shopping for. A poor PSC band on a recently adopted flag is one more line in the same profile.
It is worth keeping the bands distinct, though. A black-list flag means a ship is statistically likelier to be detained for safety deficiencies; it does not, by itself, mean the vessel is sanctioned. Those are separate questions answered by separate lists, and conflating them produces false positives. For the sanctions side, see how to check if a ship is sanctioned.
To weigh a vessel properly you want its flag, its PSC history, its age and its sanctions standing in one view — and all of it tied to the one identifier it cannot shed, the IMO number. Our deep-dive on port-state control under the Paris MoU covers the inspection mechanics in full. In the Marifest registry, every vessel file records the current flag, and the compliance screen matches the hull against the OFAC, EU, UN and UK lists — so the flag band and the sanctions verdict sit side by side rather than scattered across half a dozen authority sites.
How Marifest uses it
Marifest puts a vessel's flag next to its sanctions verdict and the rest of its file, so a poor-performing registry reads as one signal in a profile rather than a stray data point.
Every vessel record shows the flag it flies now, the input you need to read its Paris MoU band.
A move to a worse-performing registry is attached to the permanent IMO number, not lost in a rename.
The compliance screen answers the sanctions question on its own list, so a black-list flag is not mistaken for a sanctions hit.
Flag, age, ownership and screening all hang off the IMO number, giving you the full risk picture at a glance.