Flag-State Performance

Method & caveats

• Fleet is the count of active (non-deleted) vessels on each flag in our own register — the denominator for every rate.
• Detention rate is the multi-year cumulative count of all recorded port-state-control detentions (our feed spans roughly 2015–present) per 1,000 vessels in the current fleet; deficiencies per detention indicates how severe each detention was. Both come from port-state-control records. Because the numerator is a coverage-weighted cumulative and the denominator is a live snapshot, this is not an annualised or 3-year-rolling rate like the official Paris/Tokyo-MOU flag-performance lists, and it is comparable across flags only insofar as our feed coverage is even.
• Casualty rate is casualties per 1,000 fleet vessels. It is shown for context only and is not used in the grade for any flag. Separately, for flags whose own jurisdiction reports casualties the count is inflated by domestic reporting, so the displayed rate is flagged as coverage-biased and is not comparable across registers.
• Average age is DWT-weighted (broker convention), with a plain-mean fallback where deadweight is missing.
• Grade is A (best) to E (worst), driven by the detention rate and penalised one band for an ageing fleet. It mirrors the idea behind the industry white/grey/black lists but is computed entirely on our own data — it is not an official list. NR is not a sixth band: it marks a register whose observations are too few to score, so a 0.00 detention rate there means no record, not a clean one.