(2025-03-17) That time when I ordered a watch but got something more
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As you might already know, JDM watches are something on a different level of
both quality and the story they can tell. Up until this moment though, the
Japanese domestic models I got, like Casio OCW-T200S or Citizen PMD56-2951,
were just their "stock", out-of-factory versions. Not even to mention the
Seiko SBDC091 that doesn't seem to bear absolutely any difference from the
"global" SPB121 except the packaging. This time, however... oh man, does
this watch tell a story. And yes, it is a Seiko too.
It all began when I wanted to buy a completely different model, SBTM213, from
a local online retailer offering JDM watches (mainly Seikos and sometimes
Citizens) who had a particularly fair choice of the models made of titanium
(which is quite rare here). I had contemplated the purchase for several days
before finally placing the order and finding out that the model had been out
of stock and they hadn't updated its product page status field by mistake.
However, the seller had offered another model deemed very similar, SBTM203,
but even th
at wasn't it. I also asked whether they had SBTM341, which also seemed a good
option. The seller responded that they only had SBTM291 which they hadn't
even added onto the shop page yet. Well, I agreed on SBTM203 but the next
day the seller called me and told that he tested it and had a suspicion it
might be malfunctioning while the SBTM291 worked perfectly fine. They were
selling all the models we discussed at the same price (and they all have
roughly the same specs: titanium, sapphire, solar, full auto-calendar,
longwave sync), so I told him to send me the SBTM291 and we'd have a deal.
And yes, this watch turned out to be a much better deal than the SBTM203 and
even the SBTM213 I initially planned on.
Why? First, while the specs are similar, they are not the same in terms of
longwave synchronization bands they actually support. SBTM213 can only
receive JJY signals, being similar to my Citizen PMD56 for that matter.
SBTM203, being powered by an older-generation 7B24 movement, can only
receive JJY, BPC and WWVB signals. SBTM291 (like SBTM341 I asked about), on
the other hand, is powered by a modern 7B75 movement and has a 6-band
receiver: like modern Casios, but it's much more sensitive here. So, in the
very next morning after I got this watch, adjusted the bracelet and set the
timezone properly, I found out that I had received the DCF77 synchronization
signal during the night without even having to take the watch off my wrist.
And I still live in the reception area that generally is deemed unstable, so
this definitely is impressive. And even when there's no signal, adjusting
the time manually is a no-brainer and fully resembles the way it's done in
my PMD56. Much better than with a "dumb" quartz and pretty much any mech, to
be honest.
Second, the looks. Although there is a chapter ring with the timezone codes
(which the 341 doesn't have btw) around the dial, it's not nearly as
obtrusive as I thought it might be. But the dial itself doesn't have any
other writings in the middle, except the Seiko logo itself, whereas the
SBTM203 also has the words "Radio wave control" and "SOLAR" and the SBTM213
also adds the word "TITANIUM" on the bottom of that. Like, come on, guys, I
know it has radio wave control, I know it's made of titanium and I know it
has solar charging, why do you need to remind me of that every time I look
at the watch face? So, I'm glad the SBTM291 doesn't have all that wording on
the dial despite having some room to place it by being bigger in size (only
slightly bigger, still under 40 mm). What it does have though, and this even
is a win over SBTM341, is a white-on-black date window which doesn't look
out of place at all. Finally, and this is a particularly nice touch, in
addition to the hour/minute hands, all markers are lumed, and I mean all of
them, even the 3 o'clock one where the date window resides. And the lume pip
on the 12-hour position is slightly longer to be able to easily discern the
watch position in the dark. The lume itself isn't particularly strong but
just enough for such a watch type. As far as I understand, SBTM213 only has
lume on the hands and four cardinal positions, and SBTM203 has no lume at
all.
Now, to the interesting parts. As of now, this watch officially belongs to
the "Seiko Selection" series (not Brightz/Spirit/etc), and if you know how
the casebacks look like there, you'll remember that the upper part of the
caseback is basically empty, the Seiko logo is roughly in the middle and all
the additional info is below. With this particular watch, however, the first
thing I noticed was the additional custom engraving to the top of the logo.
The only Latin part of that engraving is the word YAMANAKA, all other
inscriptions are Kanji and occasionally digits, no kana. From what I managed
to translate, the engraving says something like "commemorating 10 years of
service at Yamanaka Co. Ltd / reiwa year 5 month 6". Unfortunately, it is
impossible to determine which exactly Yamanaka Co. Ltd has been mentioned
there because even the most superficial Web search easily reveals at least
six Japanese companies with the same name, but I might suppose it's the
biggest one which trades nonferrous metals and produces industrial chemicals
among other things. The "reiwa year 5 month 6" is something that baffled me
for some time until I found out that this is one of the native forms of
Japanese date system. The "reiwa" imperial era began in May 2019, so
considering this the first year and month of the era, we add 4 to the year
and 5 to the month respectively, getting the date of October 2023. According
to the serial number though, this watch had been manufactured in October
2022.
So, what does all this tell us? This particular watch was intended for
someone who started working at one of those Yamanaka companies in October
2013 and was to be given to them (most likely him, since the watch design is
quite masculine) in October 2023. This engraving had been ordered at Seiko
itself because it was done before putting the packaging protective film on
the caseback (and I usually can tell the difference whether the film was put
at the factory or afterwards). And whoever ordered this engraving in October
2022 knew that the employee would stay around for at least one more year.
However, for some reason, this watch had never been worn. Maybe the awarded
employee didn't need it at all or didn't like it (a lot of Japanese men
usually have even smaller wrist diameters than me, and even 39.5mm might be
too large for them) and put it up for sale on a Japanese auction or some
other platform. Maybe he didn't even receive the watch because he left the
company shortly before he was to be awarded or something else happened to
him, and the upper management didn't have anyone else to give the watch to,
so they sold it to a third party. To be honest, I never owned a watch
surrounded by so many questions. Which exactly Yamanaka company gave away
solar titanium Seikos to their loyal employees? Why wasn't this SBTM291 ever
worn? What happened to its intended owner? Where has this watch been between
Oct 2023 and Mar 2025 (when the local seller I got it from received it to
their warehouse)? A shroud of complete mystery that probably will never be
solved, a secret that an unknown Japanese worker might take to his grave.
Speaking of secrets, I also have been thinking about the timezone chapter
ring in the context of my previous post. Since every city code is placed
against a particular second/minute mark and there is a gap of at least 1
second between them, I have thought it would make a straightforward, albeit
rather crude, homophonic substitution table. After brainstorming several
different approaches, I believe I've found the simplest one:
1. Locate the letter anywhere on the chapter ring. For the PAR/BER timezone,
ignore the "PAR" part.
2. If the letter is the first in the code, copy the second number "as is".
3. If the letter is the second in the code, copy the second number + 1.
4. If the letter is the third in the code and the gap to the next code is 2
seconds, copy the second number + 2.
5. If the letter is the third in the code and the gap to the next code is 1
second, copy the second number + 60. If the result is over 99, you must
choose another city code to encode this letter.
6. Since there are dedicated "Y" and "N" letters on the dial, the short
messages "yes"/"affirmative" and "no"/"negative" shall be encoded as 10 and
20 respectively. Hence, the letter D cannot be encoded as 10 and the letter
K cannot be encoded as 20 under any circumstances.
Note that we don't have any instances of the letters V and Z on the chapter
ring, so we must encode V like W and Z like S.
As an example, let's encode "NoSmoking" with this method:
* We can encode "no" as a single glyph 20.
* Let's locate an S: one of the options is SYD against the 25th second. S is
the first letter in SYD, so we encode it as 25.
* Let's locate an M: we have a single option (MDY) against the 34th second,
so encoding as 34.
* Let's locate an O: one of the options is LON against the 0th second, O is
the second letter, so adding 1 and encoding as 01.
* Let's locate a K: I'd use KHI against the 13th second, the first letter -
encoding as 13.
* Let's locate an I: CAI - 6th second - 3rd letter - overlapping - adding 60
and encoding as 66.
* Let's locate an N: the easiest one would be NOU, 28th second, the first
letter, encoding as 28.
* Let's locate a G: no other choice than to use WLG, 30th second, the third
letter, overlapping, adding 60 and encoding as 90.
So the final encoding result of "NoSmoking" is 2025340113662890. Note that we
could use a different option to encode S, O, K, I and N, resulting into a
different but still valid encoding.
I'd like to call this a "Seiko cipher" but this is not a cipher per se, just
an encoding scheme. This can be used, however, with other pen and paper
encryption systems that require plaintext to be in the form of decimal
digits. Effectively, the ring itself describes the following homophonic
substitution after applying the above rules and restrictions:
This table might not follow the overall accepted frequency patterns and other
good practices of implementing homophonic substitution schemes, but the main
beauty of it is that it can be fully reconstructed by hand using the above
rules and the Seiko's timezone chapter ring. Of course, you don't even have
to reconstruct the table in order to use this encoding, but it just makes it
more convenient in some cases.
On top of that, this is not the only encoding scheme that you might use.
Since we have 24 timezone codes, and 24 + 36 = 60, you could use the
timezone codes as a sort of codebook or a syllabary, whatever fits most
(with the predefined meanings only known to you and your other communication
party) and encode individual letters and digits with the remaining 36
positions on the dial, occasionally adding 60 if the result still fits into
two digits, or even just start encoding individual characters at the
position 60 and leave the entire dial for the codebook construction.
Thereafter, everything else is up to your own fantasy. An example of such a
codebook in a hypothetical spy setting could include some easy mnemonics,
such as DEN = safehouse ("den"), WLG = will go/well-going/willing, NYC = not
yet confirmed, CAI = call, LAX = located at, LON = located on-site, DAC =
drop at coordinates, KHI = kill/hit, BKK = back, MDY = underway ("Midway"),
TYO = time, SDQ = send, PDL = prepare for delivery, SYD = status (can be
followed by 10 or 20 for success or failure), HNL = help, CHI = change and
so on. With these example mnemonics, "call back at" (in the context of time)
could be encoded as 061823 when we plug the corresponding marker values for
CAI, BKK and TYO, "status not yet confirmed" could be encoded as 2548 when
we plug the marker values for SYD and NYC, and "help underway" could be
encoded as 3634 when we plug the marker values for HNL and MDY respectively.
Well, I guess that's it. I don't remember the last time I encountered a watch
that gave me so much to talk about. The overall specifications and
construction materials, extreme wearing comfort, the exterior design, the
possibility of non-standard timezone code usage, and the totally unexpected
connection to some deep Japanese culture, both national and corporate... All
of this easily places this particular Seiko SBTM291 into the top-3 of my
collection, I'd even say on par with the PMD56. Now, it would be really hard
for me to choose between these two if I had to only keep one of them. So,
let's hope that I won't have to.
