Hello all. Some years ago being an academic as well as a power squadron member, I did extensive research on flags, burgees, signals, colors and other identifications used aboard marine small craft. As far as I know having consulted with the Library of Congress there are no present day laws or rules for flying identification signals upon your boat. EXCEPT for many of us, we follow Military rules (which would include the US Navy) which are in existence--it just doesn't always apply to us civilians. Chapman's has been in existence since approximately 1915 from the urging of the then Secretary of the Navy, F. D. Roosevelt who asked Chapman to put together a small booklet to assist private citizens "...interested in fitting himself to be of service to his Government in time of war." (World War I) That request included flying flags and signals from your boat.
Most of our flag etiquette has been borrowed, so to speak, from Europe and their great fleets of ships both military and private. The reason we fly the burgee (a signal of identification) is that it was traditional to dock a ship on the port side and so to let others know who they were they would fly a flag from starboard side facing out into the harbor.,,,hence flying the yacht club burgee from the starboard spreaders.
Flying a national (or company) flag at the stern, often off the gaff of the main sail was that was the most obvious place to fly it. I am curious as to the remark that it was because it was over the captains quarters. I'll have to follow up on that thought. And you didn't have to fly the flag of your nation--it could be an owner's flag or the flag of another nation just to get close to it to engage it in battle.
An interesting bit of history--ports along the east coast of the United States would tax commercial vessels coming into their port however private vessels of leisure were not taxed. So as to not have the port come out to greet (tax) you, the private mariners sought a signal that would make them tax exempt and that was the American flag but with a fouled anchor in the blue field (this law was established about 1849). It was discontinued if my memory serves me sometime in the 1930s. But we yachtsmen liked it and so it has remained a flag of choice. You can fly it anywhere you want but it doesn't represent anything except you like the flag....and foreign countries don't recognize it anyway.
Flying the American flag (the Ensign) from the stern of your boat is a tradition but you could fly it from the bow--as long as you could put up with fellow boat owners suggesting your ancestry. In recent years a practice of flying it from the aft shroud about three quarters up has come into practice. The problem most skippers remark is that when anchored and no breeze the flag droops around the shroud. But it is duable and there is no law against it. Unless, of course, you have a modern day Marlow-Hunter which has no back stay. Ah, the ironies of it all.
Can you leave the American flag up all night? Go ahead, particularly if you are sailing (or powering) through the night. And you don't have to have a light on it. I haven't been able to find out where that thought came about. Probably the military.
Tradition rules the waves in yachting (boating) and so we can fly a variety of signals from wherever we want. When I first started sailing we flew the yacht club burgee from the top of the main mast using a "pig stick." (I've never been able to find out where that term came from) It was a longish stick with eye screws situated in a manner that the most the pig stick went above the mast allowing the burgee to fly in any direction which was a help to the helmsman to find out which way the wind. But with the advent in the early sixties of electronic gear (wind direction and speed, VHF radio antennas, etc) the burgee was moved to the starboard spreaders and seems to be the main position to this day.
As someone in this discussion remarked, there are speciality flags (the Martini--raise your glass high) over the years that we yachtsmen like to fly. The pirates flag is popular and the beer mug. In the first Chapman's book there is a Church Pennant, Guest flag, and my favorite, crew's meal pennant! I suspect that would announce that no servants were available. I wonder if Bill Gate's yacht has that burgee? Another signal that has baffled me over the years is the Night Pennant. Why would they fly that?
In my part of the country (Pacific northwest) for those of us "crossing the border" (going into Canada or coming in the US), we tend to fly a courtesy flag of the country we are entering. For the most part we fly it from the starboard spreader. I've talked to several customs officials from both countries and they really don't know about the quarantine flag. In ancient days a ship would fly the "Q" or quarantine flag until processed into that country or port. In today's modern world, we use a phone or the VHF radio to contact the customs officials.
At times I fly from my starboard spreader my yacht club flag, then underneath it, the Princess Louisa burgee. From my port side spreader I fly my 12th Man flag (if you not from the Northwest--don't ask).
I live in the Puget Sound area with a fleet of large ferry boats which fly two American Flags during daylight hours, one from each end. At least one is at the stern.
And yes, some yacht clubs are quite officious in their regulations. The Seattle Yacht Club has done of good job of putting together a good list of requirements. The New York Yacht Club as well as the American Yacht Club (Rye, NY) also have suggestions as to how and where to fly your signals.
Please take my comments with a grain of salt. My memory is not as good as it ought to be and my notes are long lost in my basement. But in summation there are really no laws that say you have to fly any flag in any position....just custom. And remember, all those flags, buntings, burgees, etc. are just signals telling someone else a bit about you and your boat.
My best to you all.
Les