Digitally Curious - A Vintage LCD Watch Blog

Digitally Curious - A Vintage LCD Watch Blog

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  • Saturday, January 24th, 2009 - 8:38 pm
  • Casio GMW-15 [832] Moon Graph

  • Today's watch is the GMW-15 "Moon Graph," module 832.

    My particular example is NOS (New Old Stock), it is so shiny that it was very hard to take pictures of this watch without glare!

    The crystal on this watch is not flat nor is it mineral glass. It is a dome shaped regular quality watch glass, and therefore easy to scratch and impossible to find one in mint condition these days.

    As the name suggests--or quite literally spells out, the main feature of this watch is its moon-graph. What is a moon graph?

    The top half of this watch's display is dedicated to showing shows the moon's phase (full moon, half moon, etc) and position in the sky. Because the screen is split like this, you don't have to go into another mode to use this watch's main function. Very neat and unique!

    On the other hand, this watch is definitely a one-trick pony. For example, my modern AQF-100 has a moon phase, tide phase, thermometer, world time and analog - digital time. (The moon phase display on the GMW-15 is, of course, far superior and more detailed.)

    But if you do venture into its menu, you can also view the moon rise-time. It calculates all this information based on the user's input as shown below. You have to put in your latitude and longitude (think gps coordinates). Confused? Just read the user's manual. :)

    There are actually modern Casio watches that do the same thing, but this one is much cooler cause it's vintage. :D

    In addition to its main feature, it has the usual alarm and stopwatch. However, as with all other "graph" watches in Casio's lineup, it does not have any kind of light. What a bummer, huh? And what irony, too! You can only view the moon graph outside at night if there is a full moon! .... But then again, if you are outside at night you can just look up to see where the moon is and how big it is. You don't need a watch to tell you that!

    In stopwatch mode, the moon moves around to represent the seconds. I actually don't remember if it does anything special on the alarm.

    If you look closely at its dial, you will see the words "Moon Graph" printed on the dial. For many years, Casio used the phrase "______ Graph" on many of their watch models. Why? I suppose it's much prettier to say than "____ Plot" or "____ Display." A few entries ago I described the TGW-100 and how it says "Tri-Graph" on the dial. I also own the "Penta-Graph" "Quattro Graph" and other watches in this series. You can see some examples in my collection page.

    Often collectors will pair this watch with the CGW-50 Cosmo Phase watch as part of their "astronomy" collection. But if you look at the cases closely, case design is not identical for the GMW-15 and CGW-50. In fact, the CGW-50 shares its case design with the other "graph" watches such as the TGW-10. Those watches have decorative screws on the sides. The GMW-15 does not have these screws. However, the CGW-50 and GMW-15 are very similar in terms of module design, display layout, style and size. And they do share identical bands. Also, the GMW-15 and CGW-50 has a domed crystal, whereas the all other ?GW-### watches have flat crystals.

    (TGW-10 and CGW-50)

    Casio's model names usually give you a sense of what the watch does: TGW-10 is a tri-graph watch, the QGW-10 is the quattro graph. And although the CGW is officially the cosmo "phase" watch, you can see how it can be thought of as the cosmo graph watch. So it is somewhat puzzling that the moon graph watch is GMW-15. Honestly, I think they meant to say MGW-15 but made a typo. Or perhaps Casio already had something else that was called the MGW-15. Like a musical keyboard or something?

    If you have any questions about this watch, leave your email in the comments and I'll try to get back to you. :) And now I'll leave you with a few more views of this watch.

    By the way, I just traded this watch with a collector in Singapore. I'm sure it will have a nice home there. :D

  • Filed under: watch
  • Comments!
  • » i do have a casio moon graph 832 gmw-15 my wife june gave it to me when i was in the Coast Gnew glassauard on hill 60 at Port Kembla in the 80's early 90's. iT FASCINATED ME particularly the way the moon systems worked.I am now attempting to revive this unique instrument ,it needs a new band a battery,a new crystal(glass)and it's dignity restored, as it deserves to be 'back in service'.Maybe i can polish the crystal it's a little bit scratched.Does anyone know where i may obtain the wristband for this model watch?
  • by: patrick quinn, submitted Thursday, July 23rd, 2009 - 11:13 pm
  • » My 832 GMW-15 is still going strong after nearly 20 years, and is still my favourite watch. I was very pleased when it crossed the millenium! I have had the glass renewed by Casio (in the UK), and straps as well. It looks close to mint to me. The only thing it needs is a backlight, but although Casio has reused the moon graph technology in later (and current) watches e.g. in surfer watches to give tide info, their watches today are too big and clunky for my taste. It's like wearing a bus under your shirt cuff.
  • by: Anthony White, submitted Monday, October 26th, 2009 - 7:25 am
  • » Hello, I have a cgw-50 and the battery is dead. What kind of battery fits this watch? I kinda want to save money and buy online or at eBay?
  • by: Andy Campbell, submitted Wednesday, April 28th, 2010 - 12:28 am
  • » I have still got this watch, the GMW 15 or moon graph. Unfortunately it is no longer working and I have been trying to find a replacement for this watch, the exact same model. No luck on ebay.
    As I live in the UK I would appreciate if someone can send em a link where I can buy a replacement online preferably payable with paypal.

    Thanks in advance,

  • by: Robert Kleijn, submitted Sunday, April 4th, 2010 - 6:08 pm
  • » Dear Sr
    I would like to have a manual copy of CASIO 832 GMW-15.
    I could not find that in Brazil.
    Unfortunately CASIO Brazil don’t have that.
    I bought my CASIO 832 GMW-15, more than 15 year in other country.
    Where my I find that
    best regards
    Marcus Motta
  • by: Motta, Marcus, submitted Wednesday, June 2nd, 2010 - 7:08 pm
  • » I'm wearing my fathers CGW-50. It's in excellent condition and works beautifully. The only unoriginal piece is the band. The watch sat in a desk draw for many years and the band rotted into pieces. It was bought the year I was born (1989) and now has been passed on to me. It seems to be a rather rare watch as in I can't find a single one for sale online. I hope to keep it in my family unto 2200.
  • by: Jerggins, submitted Tuesday, July 27th, 2010 - 7:39 pm
  • » Hi, does any one of you know where i could get a new wrist band for a CGW 50 cosmo phase ?
    thanks !
  • by: Pat, submitted Friday, November 5th, 2010 - 1:46 pm
  • » I purchase one of these in Japan in 1989 and lost it over the years.

    I've been looking for one of these off and on for a few years and haven't had any luck identifying it until I found this site. Thanks!

    I would love to find one of these to purchase.
  • by: Daniel, submitted Monday, December 6th, 2010 - 8:35 pm
  • » I also have this watch. IT is one of my favorites. As one of the other posters asks, where can I obtain a band for the watch. Casio has made very innovative watches, but sometimes the bands are so unique to the watch, that event thought the watch survives, it is hard to wear.
  • by: Robert Thomas, submitted Monday, January 17th, 2011 - 4:40 pm
  • » Hello, to the person that shows the manual of the gmw-15 on the picture, I also would like to have a copy I own one of this beautiful watches but I can't find the manual or can you tell me where I can find It?, thanks A lot for the time to read and answear my question
  • by: Agustin Guzman, submitted Tuesday, January 18th, 2011 - 1:55 pm
  • » Any available seller for this casio GMW-15?
  • by: Jiun, submitted Thursday, June 2nd, 2011 - 9:24 am
  • » i found my old gmw-15 a few hours ago. battery is dead. i removed the case but i couldn't figure out how to open the latch that holds the battery. helps would be appreciated.
  • by: sebo, submitted Tuesday, January 1st, 2013 - 1:50 pm
  • » I entered here to findout if Casio related (at last) the successor of this legendary watch but... it's time to say my opinion about...him! Back on 1991 just few months before i go to northern iraq for a peacekeeping mission with UNGCI Forces my brother gave to me one lightly second handed GMW-15. To say the truth i didn't like it with the first sight but i needed one cheap,small,light,water proof,LCD Casio! Af course i made the proper adjustments GMT,longitude and latitude and since i arrived there i could show,no matter if it was day or night, without any compass, where approximately had to move to reach a place,or if we where going to a wrong direction if someone else was guiding us, just watching the moon and... my watch, what time exactly was the moon's or the sun's arise, if the night would be with or without any light etc... leaving my colleges with!!!??? on their faces.(there wasn't those days watches with compass features). i can't say that/if this save my life but it was very helpful (still is, it works perfectly and the lithium cell CR1616 battery that takes lasts for five years every time i replace it). Few months later at 1992 i found one brand new GMW-15 like mine at the market of Dohuk and i gave it as a gift to my young friend 14years old NINOS, the son of my landlord. I hope that he kept it somewhere and he still remember our friendship that borned there in the qore of the extremely flammable zone of middle east...
  • by: nikolas, submitted Monday, January 28th, 2013 - 8:15 am
  • » My GMW-15 is also still working after 20+ years, (I got it in the early 80's), the watch glass is a bit scuffed so I'm going to try to find a replacement.
    It's brilliant and I can get an estimate of what the tide is doing which is pretty accurate.
    I just want a user manual now.
  • by: Dave Ford, submitted Sunday, November 16th, 2014 - 12:06 pm
  • » This watch is still working well, for me.
    It survived my motorcycle accident, where I had numerous broken bones and spent 2 months in the hospital.
  • by: Bill H, submitted Thursday, January 14th, 2016 - 8:10 pm
  • » An excellent watch. Still using it daily.
    It survived my motorcycle accident, where a 1/2 ton pick-up truck drove over me and I spent 2 months in hospital.
    I had to replace the wrist band because I think the medics must have cut the band, to get the watch off.

    Excellent write up, on this watch.
  • by: Bill Hopkins, submitted Tuesday, April 18th, 2017 - 2:58 pm
  • » I had this watch and still good conditions
  • by: ferry-indonesia, submitted Monday, March 18th, 2019 - 11:21 pm
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