Monochrome Watches
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The Citizen Promaster Mechanical Diver 200M NB6021 (Live Pics & Price)

A barnacle-covered 1977 Citizen dive watch pulled from a beach serves as inspiration for Citizen’s titanium diver.

| By Robin Nooy | 4 min read |

In 1983, a Citizen Challenge Diver from 1977 was recovered from an Australian beach. The watch was covered in barnacles, indicating it had been underwater for quite a few years, as these slowly build up over time. Surprisingly, it was still in running condition as the movement was shielded from water and dirt by its case. This fascinating little story serves as inspiration for Citizen’s latest dive watch, the Promaster Mechanical Diver 200M NB6021, which comes with modern tech and materials.

Pulling any watch out of the ocean and still finding it to be running after a couple of years in one of the harshest environments imaginable, is a testament to its construction. Naturally, that’s what divers are intended to be able to withstand in the first place, but mostly for short periods of time only. Being underwater for years on end is something watches are just not supposed to do, so kudos to Citizen for building a watch as far back as 1977 that could.

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It also serves as the backstory, and inspiration behind Citizen’s latest, the Promaster Mechanical Diver 200M NB6021. This pair of humble little divers is modelled after the Challenge Diver from 1977, as found on that Aussie beach. Hence, it has a pleasent retro-look and modest dimensions similar to the original. It has been updated in key areas though, with modern tech and materials, a slightly reduced height and is ISO 6425 compliant.

The new Citizen Promaster Mechanical Diver 200M is fully made of Super Titanium, something Citizen knows how to do very well. The lightweight material is treated with the brand’s proprietary Duratect hardening technology to create an ultra-resilient, scratch-resistant surface. Citizen was the first manufacturer to produce a commercially available watch made of titanium, back in 1970. This was at a time when the material was primarily being used in space and aeronautical industries. Over the years, Citizen’s expertise led to the introduction of Super Titanium, a registered trademark combining the brand’s titanium processing technologies and Duratect surface hardening process.

The case measures a reasonable 41mm in diameter and 12,3mm in height. The way it’s constructed it seems like the bezel is slightly wider than the middle case, but both have the exact same width. It does provide for an interesting visual appeal, further enhanced by the brushed finishing on the case and the polished outer surface of the bezel. This has a black or blue insert with a crisp silver 60-minute diving scale and a luminous pip inside the triangular indicator. It grips easily and turns with a reassuring feel and a smooth “click”. Its alignment is spot-on, something that matters a great deal in a tool that could potentially save your life.

The dial comes in either black or blue, with embossed rectangular indices. Each is filled with a good dose of luminous material in a retro green hue. It has quite a strong glow, which can be seen during the day as well when properly charged by direct sunlight. Time is indicated by a Mercedes-style hour hand, a sword-shaped minute hand and a lollipop seconds hand. Again, all are treated with the same green glowing luminous material. It’s covered with a flat-top sapphire crystal, with a bevelled edge and a domed underside. The date window cuts into the 3 o’clock index and is outlined in white.

Power comes from Citizen’s in-house produced Calibre 9051, which we’ve already seen in the Promaster Mechanical Diver 200M NB6004 and the Series 8 831 Mechanical NB6010 and NB6012. This automatic movement runs at a frequency of 28,800vph and uses 24 jewels. It offers a decent 42h power reserve and is regulated to run within -10 to +20 seconds of deviation per day. As we’ve learned before, this movement is anti-magnetic to fields up to 16,000A/m (approx. 200 Gauss) as close as 1cm away, which is certainly reassuring. The movement is hidden from view by a solid titanium caseback.


The blue version. ref. NB6021-68L.

The Citizen Promaster Mechanical Diver 200M NB6021 is presented with two strap options. The black dial (ref NB6021-17E) is available on a black polyurethane strap with a waffle-like embossing and titanium pin buckle. The blue dial version (ref. NB6021-68L) comes on a Super Titanium three-link bracelet with a folding clasp. The price for both models is yet to be confirmed at the time of publication but will be included once known. It will be available from Summer 2022 at a price of EUR 650 in black on the polyurethane strap, and EUR 750 in blue on the titanium bracelet.

Whichever way you look at these watches, which I have done a while now, it’s hard to ignore the rock-solid proposition. The watch looks good, feels great on the wrist, and delivers a solid performance in key areas. Everything feels sturdy despite the low weight, and it will surely not disappoint on leisurely jumps in the pool, the occasional recreational dive or otherwise. It’s just a good, no-nonsense, ISO 6425 compliant dive watch, period.

For more information, please visit Citizen’s website.

30 responses

  1. Hi Scott Free,

    Thank you for the comment. I’ve had the watch myself for the pictures, and it is definitely not 46mm wide. When writing the article I measured the case and bezel with a digital calliper and both come in at 41mm across. I have contacted the brand for clarification.

    All the best, Robin.

  2. Hi Oscarito,

    Thank you for the comment. I’ve had the watch myself for the pictures, and it is definitely not 46mm wide. When writing the article I measured the case and bezel with a digital calliper and both come in at 41mm across. I have contacted the brand for clarification.

    All the best, Robin.

  3. Citizen has let us know the size on their website is wrong, and will be corrected.

  4. Citizen has let us know the size on their website is wrong, and will be corrected.

  5. Is the bezel 60 click? 120 click? I did not see this in your specs. Thanks.

  6. Después de sacar un reloj tan “Citizen” como el Kraken, este seudo homenaje a Rolex hace lucir falsa a la gran marca asiática

  7. Interesting back story, nicely proportioned with attractive dial and hands. Looks like a good proposition, depending on price of course.

  8. Agree with Dan, I would love to know the lug-to-lug measurement on these.

  9. I like it. With the NB1050 series, the Series 8 and the 0200, Citizen launched very nice watches reaching different price segments. This nice retro diver is another strong proposition. I hope it won’t be too expensive.

  10. I’ve been wanting Citizen reissue their vintage divers. I’m so wanting this.

  11. Not bad, but does it have a metal bracelet that can be switched out?

  12. I like it a lot. Sad that only the blue one will be available with the titanium bracelet. How silly is that? Many brands to this and I don’t know why. The customer is the only one who should be able to choose on which strap or bracelet he wants to buy the watch. So I wanted the black one but won’t buy it on rubber. Sorry Citizen, stupid decision.
    It measures 41 mm. Check the link.

  13. @Reto, I’d take over your black strap, for the black face metal one 😁

  14. Yes I would love to have this watch in Orange or Yellow. That would be a great summer watch and strand out of the crowd.

  15. Have a divers titanium.not this model wco drive…bezel is probably aluminum as I does not say..also the bezel has the worst cluck action ever…Mine is all titanium but not sapphire which let’s it down..I will never buy a divers watch again unless it has sapphire crystal. If my model had sapphire and better buyer it would be top notch.I got onto cirizen to see if I could change from mineral to NO watche only comes what it came in they said.

  16. Great looking watch but I was hoping there would be a JDM version with “Made in Japan” somewhere on it.
    I notice that there’s no writing on the bottom of the dial; also in the pic of the caseback, there seems to be a gap where some writing should be. Does it have “Mov’t Japan” written in that spot? I have my doubts as to whether there’s an empty space on the caseback.
    Was it photoshopped out?

  17. @Patrick – there’s a mention on the dial (really at the bottom, and not really legible, but you can see it on one of the closeup images) that says “JAPAN MOV°T 9051-“

  18. A good review, at last, with no whinning about the bezel action (mine is fine) and on the supposedly too smal crown… Enough with oversize crowns, already: this one never digs in wrist in any position at is fully functional. Lug to lug is 48.5 to 49mm depending on sources. Thanks!

  19. @ARBcuentatiempos ¿Homenaje a Rolex? Perdón, pero creo que no sabes ni lo que has escrito. El circulito “Mercedes” de la aguja horaria ya lo tenía el Fujitsubo original de finales de los 70, y sinceramente, si lo dices por eso, el reloj en su conjunto, no tiene nada que ver con un Submariner. Citizen no se quiere parecer a Rolex, en absoluto, sin embargo, sí que hay otras marcas, que sin parecerse a la firma de la coronita, suben y suben sus tarifas para asemejarse, cada vez más, y ser más elitistas de lo que ya son. Te hablo de Omega y su Seamaster, por ponerte un ejemplo. En fin, que sigo intentando ver en que se parece un Submariner y el Fujitsubo nuevo…

  20. Hola ARBcuentatiempos

    Aaunque sea de color negro como el Submariner, yo veo que está mas cerca del Citicen comido en percebes que hay al principio del artículo

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