What Port State Control actually is
Port State Control is the right of a country to inspect foreign ships calling at its ports, to verify they meet the international conventions the ship's flag state has signed up to — STCW, MLC 2006, SOLAS, MARPOL, and others. PSC doesn't replace flag-state or classification-society oversight; it's a safety net, coordinated regionally through memoranda of understanding such as the Paris MoU (Europe/North Atlantic), Tokyo MoU (Asia-Pacific), and similar regimes elsewhere, plus the US Coast Guard's own regime in US ports.
What an inspector looks for on hours of rest
A PSC officer checking hours of work and rest typically:
- Requests the ship's rest-hour records (paper or electronic) for a sample of crew, usually covering the weeks before the inspection.
- Compares recorded rest periods against the watchkeeping schedule, the deck/engine log, and sometimes CCTV or access-control data, looking for numbers that don't add up.
- Talks to crew directly — informal interviews are a standard, and often the most revealing, part of an MLC inspection.
- Checks that records are signed by both the seafarer and a responsible officer, and that a copy has been given to the seafarer, as MLC requires.
Why this is one of the most-cited deficiency categories
Annual reports from the Paris MoU and Tokyo MoU have repeatedly flagged hours of rest as one of the top MLC-related deficiency categories, and both regimes have run dedicated concentrated inspection campaigns (CICs) specifically targeting it. The recurring problem inspectors describe isn't usually a company that never thought about rest hours — it's records that have been adjusted after the fact to look compliant, often because the underlying schedule genuinely wasn't. Numbers that are suspiciously uniform, rest periods that exactly hit the minimum every single day, or records that don't match the ship's actual workload are classic red flags.
What a deficiency or detention actually means
If an inspector finds a shortfall, the outcome depends on severity:
- Deficiency noted — recorded against the ship, with a timeframe to correct it. This still counts against the ship's and company's inspection history and risk profile.
- Detention — for more serious or safety-critical findings (for example, a pattern suggesting genuinely fatigued watchkeepers, or falsified records), the ship can be detained in port until the issue is resolved. Hours-of-rest violations are explicitly within the range of findings that can justify an MLC-related detention.
- Higher future scrutiny — under risk-based targeting schemes, deficiencies and detentions raise a ship's and company's risk rating, leading to more frequent and more thorough inspections going forward.
A detention isn't just a paperwork problem — every day in port costs the operator money, disrupts the schedule for the whole itinerary, and (for a cruise ship) can mean guest-facing consequences. It's also, separately, a genuine safety issue: the record exists to catch a fatigued watchkeeper before something goes wrong, not after.
Where a calculator like this one fits in
None of this replaces your company's official rest-hour recording system — see how rest hours are actually recorded on board. What a quick, independent check can do is catch a problem before it becomes a record that has to be explained to an inspector: if a schedule doesn't add up, better to know that from the roster than from a PSC finding.