An Illustrated Guide to Maritime Signal Flags | Hacker News Reader

An Illustrated Guide to Maritime Signal Flags

rabbitwaves.ca

161 pointsgaws45 comments

So I just read the other thread about the K language[1] and how it's so-very-concise syntax made the author feel certain ways.

But that has nothing on this! From page 70 of the International Code of Signals[2], we find that PG 2 means, "I am dazzled by your searchlight. Extinguish it or lift it."

Not bad, but what if you reply with "AX 1"? Lots going on there! "Shall I train my searchlight nearly vertical on a cloud, intermittently if possible, and, if your aircraft is seen, deflect the beam upwind and on the water to facilitate your landing?"

[1] https://news.ycombinator.com/item?id=41886051

[2] https://rabbitwaves.ca/media/docs/ics_pub102bk.pdf

I have a copy of the International Maritime Organisation (IMO) Code of Signals on my bookshelf.

3 letter medical flag codes include:

MKH Foreskin will not go back to normal position

MKI Patient has swelling of the testicles

MLF Patient has Delirium Tremens

It's a comprehensive book to say the least!

I wonder how many times MLF has been used for a ship’s captain?

Strange there's no flag meaning "Discard all previous/following flags".

YN Cancel my last signal/message

Or in the case of medical flags...

MPR Patient has died

might do the job.

Y38.5 - medical diagnosis code indicating injury caused by terrorism involving the use of nuclear weapons.

This is from 100 Rabbits. Great job!!

One of my favorite flag signals is, “Nothing can be done until high tide.”

US1 Nothing can be done until daylight. US2 Nothing can be done until tide has risen. US3 Nothing can be done until visibility improves. US4 Nothing can be done until weather moderates. US5 Nothing can be done until draft is lightened. US6 Nothing can be done until tugs have arrived.

I liked the Flag Semaphore page it linked to, but it raises the question: Why are the letters almost, but not quite in clockwise order?

If you sort by clock position, you get:

A B C D E F G H I K L M N O P Q R S T U Y Cancel # J V W X Z

Was it invented by someone whose alphabet didn't have J, V, W, X, Z?

Fun fact based on the bottom panel: the peace sign (inverted y) is based on the flag semaphore signs for N and D, originally standing for Nuclear Disarmament.

This sounds like one of those ridiculous "facts" that gets passed around by word-of-mouth despite seeming suspiciously just-so.... and yet in this case, it appears to totally check out.

The alternative explanation was that the peace sign is an abstraction of the foot of a dove.

I'd go with the semaphore explanation.

Vaguely related: "Wuthering Heights in Semaphore" https://m.youtube.com/watch?v=kqiUGjghlzU

This seems like a great system, but in many years of sailing I've never encountered it actually used. For the most part is only possible to be used by large commercial vessels, but those vessels already have a dozen other redundant communication systems that are clearer and faster. Operators of small private vessels aren't likely to even know this system exists, not alone carry all of these flags, a code book, and a system for hoisting flags.

Yes. Anything serious is internationally required to carry (and many smaller things would be required by local laws, or strongly advised to carry anyway) a modern digital maritime radio - the technology is called DSC, Digital Selective Calling.

Yes- and even many cheap handheld VHFs have DSC nowadays.

I have only seen it on US navy vessels, I have never seen it used for communications, but they like to put up the ships id on the flags, And I always enjoy breaking out the manual and fumble my way through deciphering the flags when I see them.

It's a relic from the age of sail. Example from a few minutes googling: https://tegfan.net/2014/09/05/the-windrush/

Trafalgar (1805) https://web.archive.org/web/20060919112358/http://www.nelson...

In one of the Aubrey&Maturin books, in order to encourage their sailors to ask the local women to dance, Aubrey decorates a ballroom with a hoist equivalent to: http://www.wightmistress.com/wightmistress.com/IHYC_Flag_Eti... , engage the enemy more closely

A blue water sailing vessel might have a yellow Q flag on board for 'quarantine', signaling for officials to come document the arrival in a foreign port.

For more on 'pronunciation' see:

* https://en.wikipedia.org/wiki/NATO_phonetic_alphabet

IMHO it's very useful for IT/computer people to have this memorized as it is fairly common to have to spell something out to someone orally (over phone, video call, in office).

Even day-to-day life: to spell your personal name or street name.

In my experience, normal people are quite confused by this. I've heard "Is that Juliette with a J?" and facepalmed.

In my experience people understand perfectly well but assume that you are ex-military.

> In my experience people understand perfectly well but assume that you are ex-military.

When I use phonetic alphabet on the phone, I preface it by saying, "Let me spell it in 'airline pilot': ...." (But yes, I learned it in the Navy.)

I don't know if it is just me, but it seems like english speakers have to spell out stuff a lot more than other languages (or at least my native language). I have never heard anyone having to spell out anything in f.ex a podcast in my native language, but it happens quite regular in english speaking shows. Is english more prone to have muted sounds/letters?

Yes, yes it is. My understanding is that it used to be spoken in a way closer to the written form, but it has drifted. And then there are all the loan words that retain at least some of their original pronunciation.

Here's a fun clip about it, focusing on British place names: https://www.youtube.com/watch?v=uYNzqgU7na4

It feels like magic to be able to highlight and translate the Russian and Japanese birds on macOS. Japanese bird: "Help me!" Russian bird: "I understand!" And I do too!

There are a couple more in this series here: https://rabbitwaves.ca/site/about.html

Interesting that “Oscar” is pronounced “OSS CAH” and not “OSS CAR”. Same with Victor. Must have been made in New England (northeastern US).

Or… England?

Old England.

With the new non-rhotic affectation.

Which is really getting out of hand, to the point that some English speakers are starting to sound positively French: ‘cweam’ instead of ‘cream’ the same way the French turned ‘rex’ into ‘wa.’

I blame the EU.

Ouch. My stereotypically-American US-centric bias is showing :)

I was tempted to say "parts of England"... but I wanted to mean "parts of the united Kingdom"... so... you are right :)

These pronounciations are for the International radiotelephonic spelling alphabet, often referred to as a "NATO Phonetic alphabet". For numerals procedures vary slightly, and they've chosen IMO. The sounds are chosen to try to maximize the chance that two people who know this system, even if they don't speak any shared languages, will successfully communicate the symbols intended, so they're not about how you might pronounce these words in any particular place, but rather a plausible pronunciation everybody can approximate and understand.

This makes sense. "R" is throaty in (e.g.) English and French, and a tap or a trill in many other languages.

Allow me to be pedantic: In some dialects of english.

I thought 5 was supposed to be pronounced "fife" but this page only seems to half say that. ("faif" in the first row, but "five" in the second)

IIRC in WWII the UK settled on 'fife' and nine, while the US went with five and 'niner'. Arthur C. Clarke's novel Glide Path described the adoption of fife.

This is a neat style, and I was pleased to see that the author included accessible text since the visible text on the page is all in images.

Nice cartoonishly font, clear language, nice graphics and fast to load… why can’t more pages be like this one?

It's all graphics²! I think unicode has symbols for the flag alphabet, that would be another option.

² To be fair, there appears to be alternative text for those who cannot see the graphics

Just FYI, for anyone that didn't notice (like me at first), words in a dashed box are links! There's a description of dayshapes, and lots more info about semaphore on other pages.

I really like the 3-way-handshake at the end...

I never knew anything about this. I love discovering this sort of thing!

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