The Seiko SBCM023 is a deceptive watch. At first glance, if you look at the bezel, case, bracelet and dial, it appears to hail from their line of SKX mechanical divers. The guarded crown at four o’clock position, the SKX hands, and thick lume all conspire to deceive. A closer look at the dial with its “perpetual calendar” text tells the informed observer that this is, in fact, an unusual quartz movement.
Let’s start with the impressive and somewhat unusual specifications:
- 316L stainless steel case and bracelet.
- Screwdown crown and caseback.
- Water resistant to 200m (660ft) — diving-rated according to ISO6245.
- LumiBrite lume on hands, markers, and bezel pip
- 8F35 quartz movement: 192kHz, accurate within 20 seconds per year.
- Mineral crystal class.
- 12mm by 39mm, 140g.
- Perpetual calendar.
- 10-year battery.
Please read on for the full review and pictures.
Pictured here next to the 44mm SBDX001, the differences from the SKX series are more apparent. It’s 5mm narrower, has a thinner bezel, and is quite a bit thinner to boot. The rest of the SKX series are 44mm, making the SBCM023 a very unusual Seiko indeed. You can also see from this picture that the dial is actually a dark grey, not black, but the difference is quite subtle.
The really interesting thing about this watch is the movement. Normal quartz runs a 32kHz, and is accurate within 15 seconds per month, or 180 seconds per year. The 8F35 in this watch runs at a faster 192kHz, and is nine times as accurate at 20 seconds per year, or less than two seconds per month! By way of comparison, the most accurate quartz you can buy is the Citizen Chronomaster, at 5 seconds per year. This Seiko is within shouting distance of that, and costs a tenth of the price. Seiko didn’t stop there, though — it’s also a perpetual calendar, so the date is always correct, and the battery is rated to an extraordinary ten years. That’s quite an achievement.
If you go looking for super-accurate quartz movements, you’ll notice that many of them are put into semi-formal watches like the Citizen. The SBCM023 is a full-on diver’s watch with a unidirectional 120-click bezel, screwdown crown, diver’s bracelet extension, 200m rating, and super bright lume. Combined with the lower height and an excellent bracelet, you have one of Seiko’s most versatile watches ever made. This watch can go from the dive boat to the blue suit with effortless ease as though it were a more accurate Submariner. It won’t demonstrate your income like a Rolex might, but for the man (or woman, actually) wanting a single watch that does it all, the SBCM023 is a very good choice.
The bracelet is excellent: solid links, double pushbuttons with fliplock, fixed-length diver’s extension, nicely and evenly brushed with polished sides and bevelled clasp. The links are held with the usual pin-and-collars, and the clasp has a generous four micro-adjustments. The end links are hollow, which I consider a minor negative. Drilled 20mm lugs make changing straps or bracelets easier. Case and bracelet are finished and surfaced to a noticeably higher level of quality than the SKX series; very enjoyable to wear.
In the profile picture, you can see how the lines of the lugs curve down around the wrist while the back-to-side curve similarly ensures comfort.
On my 7.25″ wrist, the watch seems the perfect size due to the reduced bezel width. At 39mm, it’s smaller than many of the currently fashionable watches, but it’s really perfectly balanced: very legible day or night.
I do wish that the crystal were sapphire instead of Hardlex, and an anti-reflective coating would also be a nice touch. The crystal is recessed below the angled bezel, so it has some protection against damage, but care is still warranted.
Luminosity and timekeeping performance are both exemplary. The lume is quite visible after 8+ hours, and after a month I show less than a second of error. A versatile and unfussy watch, it’s perfect for accuracy fans who aren’t within range for a radio-set watch.
List price on the Japan-only SBCM023 is 31,500 JPY, or $350 USD as of 11/09. Street price is under $250, making this a very good value.
After wearing this for a while, you’ll likely be wondering why you need to wear anything larger or heavier. Outstanding versatility, ultra-accurate movement, always-correct date, and a decade-long battery make this one heck of a killer watch. All of that functionality, and a style that is uniquely Seiko. Highly recommended.
By Paul Hubbard
Would be perfect with Solar and solid end links. However it suits a nato or rubber strap, and 10y battery makes Solar redundant if you want to check the water resistance and service it every 10 years. Would definetly have bought this if I had heard of it before I bought my current diver.