Why real cases, not hypotheticals
It's easy to treat the 10-hour daily / 77-hour weekly rest minimums as an abstract compliance number. The cases below are a reminder that they exist because investigators have repeatedly traced real accidents back to a watchkeeper who wasn't getting enough rest. Each case here is drawn from a published report by an official marine accident investigation body — the UK's Marine Accident Investigation Branch (MAIB) or Canada's Transportation Safety Board (TSB) — and linked so you can read the original finding yourself, not a paraphrase of a paraphrase.
Grounding of the dry cargo vessel Beaumont (Spain, 2012)
On 12 December 2012, the general cargo ship Beaumont ran aground on rocks near Cabo Negro, on Spain's northern coast, while on passage from La Coruña to Avilés. The vessel struck the rocks at close to full speed and was refloated by a salvage tug around nine hours later.
The MAIB's investigation found that the chief officer, alone on watch, fell asleep as a result of insufficient stimulation and probable fatigue following a recent change to his work and rest pattern. No lookout had been posted on the bridge during darkness, so the vessel continued at over 11 knots, unmanned in practice, for more than an hour before it grounded. The report also noted that the master had not delayed the ship's departure to allow the crew adequate rest beforehand.
Full report: MAIB Report 14/2013 — Beaumont.
Grounding of the bulk carrier Tundra (St Lawrence Seaway, 2012)
On 28 November 2012, the bulk carrier Tundra ran aground in the St Lawrence Seaway, at a location where another vessel had grounded years earlier. Damage was limited to hull scratches and a bent propeller blade, with no injuries or pollution — but the investigation by Canada's Transportation Safety Board is notable for how directly it traced the accident to fatigue rather than a navigation or equipment failure.
The pilot conning the vessel had an undiagnosed sleep disorder (later confirmed as mild obstructive sleep apnea and shift-work sleep disorder) that had gone unaddressed since an inconclusive evaluation years earlier. The TSB concluded that his ineffective monitoring of the vessel's position resulted from diminished situational awareness caused by fatigue, and that the abrupt drop in his activity level in the moments before the grounding was consistent with a brief involuntary "micro-sleep."
Full report: TSB Canada Marine Investigation Report M12L0147 — Tundra.
Loss of the fishing vessel Silver Cloud II (Scotland, 2025)
In the early hours of 14 October 2025, the prawn trawler Silver Cloud II struck rocks near Lochinver, on Scotland's north-west coast, while the skipper was alone on watch with the autopilot engaged. All three crew got safely onto the rocks and were rescued by the RNLI, but the vessel later broke up and was declared a total loss.
This is the case most directly on-topic for a rest-hours calculator: the MAIB found the skipper had been fighting flu-like symptoms and had logged only 6, 6.5, and 7.5 hours of rest on the three days before the grounding — every one of them below the STCW/MLC 10-hour daily minimum. The report concluded that the combined effect of acute fatigue, physical illness, and working during the circadian low between 2 a.m. and 6 a.m. substantially increased the likelihood of impaired alertness and unintentional sleep. An alarm system without a visual alert or cabin repeaters meant nothing woke him before the grounding.
Full report: MAIB Report 17/2026 — Silver Cloud II.
What these three cases have in common
Despite covering a cargo ship, a bulk carrier, and a small trawler across three different flag states and investigating authorities, the same pattern shows up each time: one person, alone on watch, whose rest in the hours or days beforehand had already fallen short — and no second layer of protection (a lookout, a working alarm, a schedule change) caught it before it became a grounding. None of the three involved a single dramatic rule-breaking event; each involved an ordinary, incremental rest shortfall that built up until it mattered.
Where this connects to your own schedule
You don't need to wait for an inspector or an accident report to find out that a schedule doesn't leave enough room for rest. Running a planned or actual roster through the rest hours calculator on this site checks it against the same STCW/MLC minimums referenced in all three reports above — before it turns into a line in someone's investigation.
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