There are also the patrol boat staff to worry about. They never complain but it's wrong to make them carry on until dark.
If people don't get a finish when the faster sailors do, they might be drifting about with a dying wind and get timed out anyway. If it's a two lap race and it takes an hour and people have only sailed one lap in that time, they are unlikely to finish another lap in the half hour time limit. They end up with DNF instead of a place.
Who's the more foolish; the fool or the fool who follows him?