Extremely briefly:

On one hand, fatigue is an enormous problem, affecting one's ability to function effectively in any environment, let alone offshore yachting. You might argue that people should be allowed to put themselves at risk, and I would probably not take huge issue with that, so long as those involved are happy to be left to their ends rather than expecting rescue.

On the other hand, I disagree fervently with those who suggest that keeping a good lookout is something that can justifiably be excused the single-handed fraternity.