An Illustrated Guide to Maritime Signal Flags

(rabbitwaves.ca)

161 points | by gaws 258 days ago

15 comments

  • function_seven 254 days ago
    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

  • GJim 254 days ago
    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!

    • greggsy 254 days ago
      I wonder how many times MLF has been used for a ship’s captain?
    • ragazzina 253 days ago
      Strange there's no flag meaning "Discard all previous/following flags".
      • GJim 253 days ago
        YN Cancel my last signal/message

        Or in the case of medical flags...

        MPR Patient has died

        might do the job.

    • nocoiner 253 days ago
      Y38.5 - medical diagnosis code indicating injury caused by terrorism involving the use of nuclear weapons.
  • wrycoder 254 days ago
    This is from 100 Rabbits. Great job!!

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

    • ahazred8ta 254 days ago
      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.
  • raldi 253 days ago
    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?

  • acidburnNSA 254 days ago
    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.
    • raldi 253 days ago
      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.
    • euroderf 253 days ago
      The alternative explanation was that the peace sign is an abstraction of the foot of a dove.

      I'd go with the semaphore explanation.

  • roywiggins 253 days ago
    Vaguely related: "Wuthering Heights in Semaphore" https://m.youtube.com/watch?v=kqiUGjghlzU
  • UniverseHacker 254 days ago
    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.
    • pjc50 253 days ago
      It's a relic from the age of sail. Example from a few minutes googling: https://tegfan.net/2014/09/05/the-windrush/
    • sellmesoap 253 days ago
      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.
    • somat 253 days ago
      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.
    • tialaramex 254 days ago
      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.
      • UniverseHacker 254 days ago
        Yes- and even many cheap handheld VHFs have DSC nowadays.
  • throw0101c 253 days ago
    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.

    • fastasucan 253 days ago
      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?
      • Maakuth 252 days ago
        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

    • n_plus_1_acc 253 days ago
      In my experience, normal people are quite confused by this. I've heard "Is that Juliette with a J?" and facepalmed.
      • petschge 253 days ago
        In my experience people understand perfectly well but assume that you are ex-military.
        • dctoedt 253 days ago
          > 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.)

  • lelandfe 253 days ago
    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

  • cbsks 254 days ago
    Interesting that “Oscar” is pronounced “OSS CAH” and not “OSS CAR”. Same with Victor. Must have been made in New England (northeastern US).
    • tialaramex 254 days ago
      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.
      • euroderf 253 days ago
        This makes sense. "R" is throaty in (e.g.) English and French, and a tap or a trill in many other languages.
        • f1shy 253 days ago
          Allow me to be pedantic: In some dialects of english.
    • raldi 253 days ago
      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)
      • ahazred8ta 251 days ago
        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.
    • brickers 254 days ago
      Or… England?
      • cbsks 254 days ago
        Ouch. My stereotypically-American US-centric bias is showing :)
      • pc86 254 days ago
        Old England.
        • kevin_thibedeau 254 days ago
          With the new non-rhotic affectation.
          • eadmund 253 days ago
            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.

      • f1shy 253 days ago
        I was tempted to say "parts of England"... but I wanted to mean "parts of the united Kingdom"... so... you are right :)
  • nnf 254 days ago
    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.
  • NKosmatos 254 days ago
    Nice cartoonishly font, clear language, nice graphics and fast to load… why can’t more pages be like this one?
    • Tepix 253 days ago
      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

  • graypegg 253 days ago
    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.
  • f1shy 253 days ago
    I really like the 3-way-handshake at the end...
  • foo42 254 days ago
    I never knew anything about this. I love discovering this sort of thing!