Fatigue is a state of feeling weary, tired or lethargic that results from physical or ­mental work, anxiety, harsh environments or loss of sleep. It is different from simple tiredness through missed sleep.

With up to 400,000 seafarers stranded at sea or at home by travel restrictions during the Covid-19 ­pandemic, many crew have worked months beyond their contracts and regulatory limits, and the industry has sounded the alarm over their well-being.