The Fatigue Blind Spot

Why maritime's most pervasive safety risk remains largely invisible — and what five years of PSC data reveal when you know where to look

Of the 1,022 maritime casualties involving IMO-numbered vessels recorded between 2021 and 2025 across three major Port State Control regions, exactly 14 cited fatigue as a contributing cause. That is 1.4 percent. The International Transport Workers' Federation estimates that fatigue contributes to 25 percent of all marine casualties.

Somewhere between those two numbers lies the true scale of a problem the industry has known about for decades, regulated through paper records, and consistently failed to measure. The gap is not a statistical footnote. It is the central crisis of maritime safety measurement — and it has consequences for every operator, port authority, insurer, and regulator with a stake in what happens when a fatigued officer of the watch encounters a developing situation at 0340 hours.

The industry does not have a fatigue problem it cannot solve. It has a fatigue problem it cannot see. Those are very different challenges — and they require very different responses.

What the Regulations Actually Measure

The international framework governing seafarer fatigue rests on three principal instruments: STCW Chapter VIII, MLC 2006 Regulation 2.3, and SOLAS Chapter V Regulation 14. Together, they represent the most comprehensive set of watchkeeping and rest-hour requirements ever adopted by the maritime industry. They share a fundamental limitation: none of them measures fatigue. They measure compliance with scheduled rest hours.

A seafarer who has spent required rest hours unable to sleep due to noise, vessel motion, or circadian disruption — and who resumes a watch in a state of genuine physiological impairment — is, in regulatory terms, not fatigued. The regulation has been satisfied. The risk has not been addressed. The proxy has become the measure, and an industry that optimises for rest-hour records rather than crew alertness has systematically mis-specified the problem it is trying to solve.

The Record That Does Not Reflect Reality

The 2024 ITF Seafarers’ Trust and World Maritime University report “Quantifying an Inconvenient Truth” puts numbers to what operational experience has long suggested. Port State Control inspectors reported compliance rates above 90 percent. The seafarers on those same vessels estimated true compliance at between 11.7 and 16.1 percent. These tools are not measuring the same thing.

Almost half of seafarers in recent surveys reported working weeks of 85 hours or more. One in four reported having fallen asleep while on watch. Andrej Sokolov — a Chief Engineer with more than 30 years of sea service, including three and a half years in financial loss-prevention programmes on petrochemical tankers and certification as an SMS Auditor — describes the result with precision: a system in which hundreds of thousands of officials across the inspection, flag state, and operator ecosystem perform, in good faith, the responsible administration of a compliance record that bears a diminishing relationship to operational reality. "Can you imagine how many people are involved in this process?" Sokolov writes. "It is not their fault."

What Five Years of Data Actually Reveals

A five-year analysis of PSC inspection records and maritime casualty data across the Paris, Tokyo, and Caribbean MoUs offers a different lens — one that looks not at what the records say, but at what the records predict. The study examined 1,022 casualties involving IMO-numbered vessels recorded between 2021 and 2025, cross-referencing fatigue-related deficiency citations against casualty outcomes using logistic regression adjusted for deficiency count, detention status, ship type, and region.

The most striking result comes from a single deficiency category. Vessels cited for a defective or absent Bridge Navigational Watch Alarm System (BNWAS) showed an odds ratio of 0.26 (95% CI: 0.08–0.81) for watchkeeping casualty within the subsequent twelve months — a statistically significant protective association. No other fatigue-related deficiency category produced a significant result.

This is not evidence that BNWAS defects are safe. It is evidence that PSC inspection and citation functions as a protective intervention — that the act of identifying and recording a deficiency triggers a chain of regulatory attention and operator response that temporarily suppresses casualty rates, regardless of whether the underlying fatigue conditions have been structurally resolved.

The data also reveal a separate finding about the fleet as a whole. The odds ratio for any vessel having a BNWAS deficiency cited at inspection is 3.88 (95% CI: 1.23–12.20) — nearly four times the baseline odds. These are the vessels that most need the protective effect that inspection provides. They are also the vessels least likely to receive it consistently.

PSC inspection works — but only by triggering heightened attention, not by resolving the underlying fatigue condition. The protection is real. It is also temporary, and unevenly distributed across the global fleet.

An Enforcement Equity Problem

The protective effect of citation is the most important — and most uncomfortable — finding in the dataset. It means that PSC enforcement, where it occurs, works. It also means that vessels which are never inspected, or inspected without sufficient depth to generate fatigue-related citations, do not receive this protection.

The regional data make this inequality visible. Paris and Tokyo MoUs cited fatigue-related deficiencies at 6.1 and 7.1 per thousand inspections respectively. The Caribbean MoU cited at 2.8 per thousand — less than half the Paris rate. A low citation rate in a resource-constrained region is not evidence of compliance. It is evidence that the protective effect of inspection is not reaching the vessels that need it most. That is not a compliance finding. It is an enforcement equity finding.

The most telling number in the dataset may be the smallest: PSC officers issued just 44 STCW Chapter VIII citations across three regions and five years — fewer than nine per year across more than 226,000 inspections. STCW Chapter VIII is the convention most directly governing watchkeeper fitness for duty. MLC 2006 Regulation 2.3, covering much of the same ground through rest-hours records, generated 1,414 citations over the same period. That 32:1 ratio does not reflect a difference in underlying violation prevalence. It reflects the practical reality that MLC citations require only a document review, while STCW fitness-for-duty citations require observable evidence and officer judgment.

The Legal and Insurance Vacuum

Without an objective fatigue measurement tool, the word "fatigue" in any dispute — insurance, regulatory, or legal — means whatever the most persuasive argument says it means. Sokolov, drawing on his loss-prevention experience, states it plainly: "fatigue has become a convenient term to cover negligence, incompetence, violation of discipline — all that we call the human factor. Fatigue can be applied in favour of any side of a corporate dispute depending on whose lawyer is more experienced."

If fatigue contributes to 25 percent of casualties but appears in 1.4 percent of cause factor records, a material share of claims currently attributed to navigational error or equipment failure may have fatigue as an unrecorded contributing factor. The risk differentiation opportunity exists in the PSC database today. The analytical framework to exploit it is the missing piece.

The Question the Data Cannot Yet Answer

What this analysis cannot yet show is the true casualty burden attributable to fatigue — because the measurement infrastructure to establish that attribution does not yet exist at scale. The tools exist in occupational health research and are beginning to be piloted in maritime contexts. What has been missing is a validated framework that connects those measurements to the regulatory and operational structures that port authorities, operators, and insurers can act on.

That question is answerable. The data foundation is in place. What remains is the industry's willingness to ask what the current regulatory architecture was not designed to answer: not are the records compliant, but is the officer on watch fit to stand it.

Fix the inspection gap. Extend the protective reach of PSC scrutiny to the vessels and regions currently outside it. Then build the measurement infrastructure that makes the underlying fatigue condition visible enough to address — not just suppress.

Dr. Cecilia Hegamin-Younger holds a PhD in Measurement and Statistics, LLM in Maritime Law, MPH, and MLS. This analysis is drawn from five years of PSC inspection records across the Paris, Tokyo, and Caribbean MoUs and the IMO Global Integrated Shipping Information System (GSIS) casualty database. Practitioner commentary was contributed by Andrej Sokolov, Chief Engineer and SMS Auditor, with more than 30 years of sea service including loss-prevention work on petrochemical tankers.

The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.