I can only offer anecdotal evidence regarding hours worked by ship’s crew. It is sometimes obvious that the Master on a Master plus one Mate coaster is exhausted on occasions. This is exacerbated in poor weather. I have boarded such vessels and it is not uncommon for the Master to be resting when the pilot boards or disappear soon afterwards, blatantly ignoring his responsibilities. It could of course be argued that it is better he rests and be available at a more critical point in the passage.

I have seen crew time sheets with hours recorded in the same hand, using the same pen for a period covering a week or more. Coincidence or not?