While completely agreeing with your point on watch-keeping I am, once again, dismayed to see someone espousing the idea that merchant ships do not have anyone on watch. It is especially ironic that the "belief" comes up while we're discussing how the single-handing sailor can best figure out how to not keep a proper watch in the pursuit of sleep. Reality is that it is the sailboat, single-handed or full complement, that is more likely to not be keeping a proper lookout. The idea that it is common practise to navigate a $150 million dollar ship with no lookout is the same type of thinking that allows 16 year old boys to believe that the Ferrari dealer will let them take one out for a test drive.
Again, I fully agree with the rest of your points, especially that one is essentially relying on luck when relying on non-visual means for watch-keeping.
Why is there no advise or movement for the advocation of say International orange sails for the offshore single hander? See and be seen is the watchword for safety. Is it that they don't look "pretty"? You can always tell the ships that come out of the North Sea, where the normal conditions seem to be Force 4-6 and the whitecaps are omnipresent on a dark sea. Black hulls and white houses of ships blend in as if camoflaged. Most North Sea ships have the Bridge Deck wind dodger painted international orange for improved visibility to other ships. I don't see sailmakers even offering such an option on sails beyond the odd orange dot on a storm jib. Just a thought.
“Scientists are people who build the Brooklyn Bridge and then buy it.”
Wm. F. Buckley, Jr.