If you know these well you may pick up a win from time to time when your competitor fails to read the flags and does something wrong.
But do note the context dependence as mentioned in TFA. The "L" flag on a race course may mean "Follow this boat" or "There is a notice posted here," but on the open sea it means "Stop immediately," and in port it means "We are diseased."
Visual signalling leaves no trace and can only be seen by those who you can see. Radio transmissions can be detected by sensors you don't know are present. This is useful for navies.
They're reasonably quick, reliable and transcend language barriers.
They also work well as a broadcast method - you can hoist Flag Alpha and every ship in visual range will know you that have a diver in the water and to use caution in your vicinity, you don't need to create excess chatter by announcing it on radio every 5 minutes.
Also, when you need a laugh during a long and boring watch you can get someone junior on the bridge to read out the ICS definition for Single Letter Signal Flag Zulu.
Yeah. As someone who lives on navigable river, it's not uncommon for me to see boats flying signal flags for variety of reasons. There's not a wide range of usage here mind you - it's typically tugs and workboats flying the RY signal (you should proceed at slow speed when passing me), survey vessels flying IR (I am engaged in submarine survey work) or cruise ships flying the H signal (I have a pilot on board).
Naval vessels are kind of an interesting case though. They also fly the H flag when they have a pilot on board, but when they do so it's in combination with the answering pennant at the top of the hoist. I believe this is a standard practice when communicating with merchant marine vessels to indicate that the signal is based on the ICS rules and not the naval signal book which can mean something completely different. Naval vessels also often display their call sign using these signal flags when arriving and departing from port.
The "defunct" term is an exaggeration allowed due to the fact that the blog audience is composed of "creative" people with focus on fiction and poetry, as you can see from the referenced "Code Poems" work by Hannah Weiner; the author provided an introduction and a not-so-unrealistic status of their use (it isn't a defunct language because you are requested to know them in order to get a boating license; source: I got mine early this year).
I think that @prismatic posted it here on HN because there are people who doesn't know them and are likely to be interested (other than being bewitched by the use proposed by Mrs Weiner).
Great that it was posted. I personally am pretty interested in signal flags (possibly thanks to reading about their evolution in the fictional world of Safehold book series), and I particularly liked the idea at the end of the article.
If this subject interests you, I recommend checking out Andrew Gordon's wonderful book The Rules of the Game: Jutland and British Naval Command (https://www.amazon.com/Rules-Game-Jutland-British-Command/dp...), which (among other things) goes into great detail on how complicated the Royal Navy's system of flag signaling had become by the turn of the 20th century, the efforts of some brilliant officers to simplify it, and the disastrous wartime results that came because others clung too hard to the positions of influence mastering that system had won them in peacetime to see that it was completely unworkable in war. It's a fascinating portrait of how technical innovation and institutional inertia can collide, and what happens when inertia is allowed to win.
Nautical flags are still used for almost all of competitive sailing.
They work exceptionally well. Sailboat races are typically started between an anchored boat with a flag and an anchored buoy. There is a countdown with sound signals and flags. If the race committee decides to enact a special starting rule, they do so with a signal flag. If a boat has started early, it's indicated by a signal flag.
I'm 30 and in my life in my local fleet handheld VHFs have become popular, but even so signal flags are not going anywhere.
I can recall and draw much of the alphabet because of this: B, C, I, L, N, Z, X, S, Y, P, 1st repeater and 2nd repeater are all vital in sailboat racing.
It might seem outdated but still in use today. When entering a new country you still need to fly the Q (yellow) flag till you cleared customs / immigration.
I bought a fixed string of signal flags for my boat from West Marine for decoration. Invariably, someone will ask what it means. The fun part is leading them on with something ridiculous, like, "Cocktails at 5", or "We're sinking". Otherwise, as a sailor who has thousands of deep water miles sailing in many countries, I have never learned or used the system.
Off all things this brings to mind watching animated Tintin as a kid. At one point they are flown ahead of a ship, and is waiting in harbor for it to land. As they wait Haddock is watching these flags, only to observe them signal that the ship is found to have a infectious disease on board.
On holidays and other special occasions, Navy ships will hoist a rainbow array of signal flags up and over the mast to look pretty. (Full dress ship, [0])
The flags for full dress ship are not chosen by the ship, however. They are mandated by an instruction and all ships have to use the same flags. ([1], paragraph 705)
I'll leave it as an exercise for the reader to discern why this is so.
Marryat as well as being a distinguished naval officer was a fine writer. Mister Midshipman Easy. By comparison, Patrick O'Brien wasn't even a sailor. He was a genre writer. The parallel would be Arthur C Clarke vs Ray Bradbury. Clark proposed geostationary satellites and EME in one article, Extra-Terrestrial Relays – Can Rocket Stations Give Worldwide Radio Coverage?
Some key ones are here: http://abyc.co.za/wp-content/uploads/2013/04/ISAF_RRS_2013-2...
If you know these well you may pick up a win from time to time when your competitor fails to read the flags and does something wrong.
But do note the context dependence as mentioned in TFA. The "L" flag on a race course may mean "Follow this boat" or "There is a notice posted here," but on the open sea it means "Stop immediately," and in port it means "We are diseased."
Ain't nobody got time to spell things out.