How much does COSC mean to you?

OK, so buying new it's a guarantee that the watch will run at a certain spec. But beyond that?

Recently sent my newmark 71 off to Brendan (Webwatchmaker) to get the bezel swapped out, and figured I'd throw my omega mk40 triple date in the box and have him regulate it.

It's not a watch that omega thought could or should get COSC certification, yet upon getting it back from Brendan a few days later, its running at +1s a day. Exactly what I'd asked if he could manage (the mk40 is a PITA to set the time).

Pretty damned pleased. Goes to show that certification isn't in itself proof of a watches superiority over another or should be seen to be of added value. Interestingly that, and the newmark, are by far my most accurate watches. No fancy certificates, just some folk who pay attention to doing things right.

My PRS-18Q COSC has been running at +1 for the last couple of months, damned marvellous piece of kit.

And the thing is, a COSC-certified watch can start running out of spec as readily as a non-COSC watch so while it's a lovely little certificate to have, it doesn't mean very much to me.

When Doxa first released the 50th Anniversary SUB 300 with the COSC 2824, they had complaints about them not running within COSC spec so Doxa posted on their WUS sub-forum to say COSC was only an indication of how the movement could perform at the time of the test and timekeeping was affected by how it was worn and the environment. They're also tested without the watch - movement only. In other words, what's the point?

Anyway, which bezel did you fit and any pics?

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Originally Posted by Onelasttime

And the thing is, a COSC-certified watch can start running out of spec as readily as a non-COSC watch so while it's a lovely little certificate to have, it doesn't mean very much to me.

When Doxa first released the 50th Anniversary SUB 300 with the COSC 2824, they had complaints about them not running within COSC spec so Doxa posted on their WUS sub-forum to say COSC was only an indication of how the movement could perform at the time of the test and timekeeping was affected by how it was worn and the environment. They're also tested without the watch - movement only. In other words, what's the point?

Anyway, which bezel did you fit and any pics?

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I've read horror stories regarding Doxa, even if I love them in principal purely because if Clive Cussler. But indeed, it makes you ask what the point is.

And I went with blue 60 minute. It's not Friday yet, so I'll post a picture then. Needless to say, it is a HUGE improvement on the silver bezel and dial. It was far too bling yet sterile. Still going to send the black bezel back for refund though. Absolutely no way it can be done by someone at home.

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Originally Posted by hafle

I've read horror stories regarding Doxa, even if I love them in principal purely because if Clive Cussler. But indeed, it makes you ask what the point is.

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The current Doxa brand has no relation to the old Doxa. They bought the defunct name and have been trading on Doxa's heritage.

For me COSC means that the movement is capable of running within the criteria. So chances are that the watch will perform well as regards timekeeping. It doesn't guarantee that will always be the case though.

But not all COSC certified watches come with the certioficate.

Rolex which is by a massive margin the biggest user of the service dont issue the certificate with the watch.

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Originally Posted by Onelasttime

And the thing is, a COSC-certified watch can start running out of spec as readily as a non-COSC watch so while it's a lovely little certificate to have, it doesn't mean very much to me.

When Doxa first released the 50th Anniversary SUB 300 with the COSC 2824, they had complaints about them not running within COSC spec so Doxa posted on their WUS sub-forum to say COSC was only an indication of how the movement could perform at the time of the test and timekeeping was affected by how it was worn and the environment. They're also tested without the watch - movement only. In other words, what's the point?

Anyway, which bezel did you fit and any pics?

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I do like COSC certification as it means that the watch is capable of running within -4/+6 secs/day and I expect my COSC rated watch to run within these parameters when freshly serviced. If it didnt then I would return it for adjustment.

That said, my Submariner 14060M is not COSC rated and still runs within COSC specs as did my Moonwatch when I had it.

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Originally Posted by bedlam

The current Doxa brand has no relation to the old Doxa. They bought the defunct name and have been trading on Doxa's heritage.

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Yeah, but the Jenny company is hardly Invicta. At least its history is very much in dive watches.

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Originally Posted by ben4watches

But not all COSC certified watches come with the certioficate.

Rolex which is by a massive margin the biggest user of the service dont issue the certificate with the watch.

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I thought Rolex performed its own testing that exceeded COSC?

EDIT: just read that it still sends movements to COSC, and then performs its own tests to ensure a +/- 2 secs accuracy. That’s dedication for you.

Doesn't concern me,my life isn't ruled to the hour or even seconds.Some people put too much importance on things that aren't important at all!.

Now if my heart wasn't ticking correctly,I'd have that regulated........

Nothing.

M

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Not a whole lot. I've had COSC watches that run out of spec and non-COSCs that were spot-on. Granted there is a higher probability of COSC watches being more accurate than non-COSC, but it doesn't bother me overall. If I like the watch I'd take it in a heart-beat regardless of its COSC credentials.

I don’t place much on COSC,the last certified I owned was a new non date sub,it had to go back the time keeping was dreadfull.

To me it means a level of accuracy. Usually with the movements they are finished to higher tolerances. Non-COSC movements (from some manufacturers) may also be better than COSC, but most will not be as stable, or as capable of as good accuracy over a given period as a better movement, or a movement with better parts as standard.

If a movement has a stated <25 secs per day and you get better than that great, but don’t expect it. At least with the big brands they will regulate your watch under warranty and get it within their stated figures.

Nice to have but the premium seems high for some brands where they offer COSC and non COSC models that are at least visually the same.

I did an escapement adjustment course a few years ago. For a COSC watch to keep time within very limited parameters requires adjustment primarily of the escapement: Reduction of balance pivot endshake, closing of curb pins, adjusting pallet stone depths, and ensuring the spring is perfectly flat, on beat and isochronous.
The right amount of lubricants and a freshly cleaned movement are essential. This can take a couple of hours.

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Not one bit TBH.

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Originally Posted by Webwatchmaker

I did an escapement adjustment course a few years ago. For a COSC watch to keep time within very limited parameters requires adjustment primarily of the escapement: Reduction of balance pivot endshake, closing of curb pins, adjusting pallet stone depths, and ensuring the spring is perfectly flat, on beat and isochronous.
The right amount of lubricants and a freshly cleaned movement are essential. This can take a couple of hours.

Sent from my SM-G900F using Tapatalk

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Another factor is how well the balance is poised, I’m convinced this makes a very significant difference.

I’m not brave enough to try adjusting pallet stone depths, but closing up the curb pins and truing up the balance spring are within my capabilities. I’ve spent time correcting these factors on Omega 550/560 movements but still been unable to get all 6 positions within 10 seconds, but doing the same thing with the chronometer versions has produced better results, by process of elimination I put that down to the inherent difference in balance poise.

My recently restored 1967 Omega Constellation is a good example, despite being 50+ years old its running at around +1.5 secs/day and it seems consistent. I didn’t do anything special with it, just serviced it thoroughly and gave the hairspring a minor tweak. As I’ve said many times, a watch can sometimes be regulated/ adjusted to run between -4 and +6 but that doesn’t mean it meets COSC spec!

Nowt. The watches I own run either a little fast or a little slow. When they are worn in rotation they are set either fast or slow to run in and out of perfection over a week or two, but never more than 30/40 secs fast or slow. I never miss a bus or train.

Having worn a Spring Drive for some time COSC looks like a fail.

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Originally Posted by bedlam

Having worn a Spring Drive for some time COSC looks like a fail.

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Yup, quartz watches will do that:-)

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Originally Posted by RAJEN

Yup, quartz watches will do that:-)

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I referred to a mechanical watch with a quartz regulator. Proper quartz movements like the 9F take accuracy to a whole other level. At that point COSC is a laugh.

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Originally Posted by bedlam

I referred to a mechanical watch with a quartz regulator. Proper quartz movements like the 9F take accuracy to a whole other level. At that point COSC is a laugh.

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I am just yanking your chain.
Spring drive is a very Innovative movement and like it a lot.
Still it is a little unfair to compare with a pure mechanical movement.

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Originally Posted by bedlam

I referred to a mechanical watch with a quartz regulator. Proper quartz movements like the 9F take accuracy to a whole other level. At that point COSC is a laugh.

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Yep. My Longines VHP is good for +- 6 seconds per year, and it's well on track to achieve that. :eagerness:

Cosc / accuracy are pretty low on the list for me, much more interested in stuff like dial printing, finishing, design, wearability, and originality than strict timekeeping.


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Originally Posted by Omegamanic

To me it means a level of accuracy. Usually with the movements they are finished to higher tolerances. Non-COSC movements (from some manufacturers) may also be better than COSC, but most will not be as stable, or as capable of as good accuracy over a given period as a better movement, or a movement with better parts as standard.

If a movement has a stated <25 secs per day and you get better than that great, but don’t expect it. At least with the big brands they will regulate your watch under warranty and get it within their stated figures.

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This. Most of my mechanicals perform at either +1 or +2 spd under normal conditions and when off the wrist. However, only the COSC ones (and that just means Rolex in my case) are capable of maintaining that +1 or +2 spd even after some rather sporty use.

I took my GMT to RSC a few years ago when it was running at +6 s/d and they happily regulated it under warranty, despite being (just) within COSC parameters because they expected +/- 2 from it. On the other hand, I had to be certain that my 60th Anniversary Speedmaster was running at +13 s/d i.e. at least 1 sec outside the stated tolerance before I could take it to Omega for regulation.

Having said all of that, I don’t think I wouldn’t buy a watch that I like just because it wasn’t certified.

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Originally Posted by Curtis

my Hamilton, which is not COSC still keeps time to COSC

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My Hamilton Khaki keeps better time than COSC, in fact it’s more accurate than any of my Rolex watches and runs at just +1 spd under normal use.

COSC is a promise that the movement was tested to a certain specification before encasement in a watch. The implication, but not necessarily guarantee, is that the final product will run at these specs on purchase. As such, any non-COSC movement can run at COSC specs but if it doesn't you have no recourse to complain. My understanding is that any movement can theoretically be made to run accurately and precisely provided the regulator is skilled and patient enough. But the mark of a good quality movement is the ease and consistency in which it can be regulated.

Watches that are sold as COSC certified tend to use higher grade movements; so Glycodur balances instead of nickel, Nivarox 1 springs, and so on. In today's age of manufacture I don't know what you gain in the real world from this but if your ETA movement is COSC grade it is nice to know it can hold it's own against any industrially produced tracteur from anyone else.

So to summarise, COSC is nice to have and beyond a certain price limit - say around £1500-2000 - I would expect it. Of course, some brands like Nomos or Grand Seiko do not use COSC but adhere to very similar, if not better, standards.

Cosc or not. Once I got used to a watch that's accurate to cosc, don't wear much a watch that varies say +10s/day.

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Originally Posted by zenius

Cosc or not. Once I got used to a watch that's accurate to cosc, don't wear much a watch that varies say +10s/day.

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But a watch that's not COSC-rated can usually be regulated to run at +6 secs/day or better. It still doesn`t meet COSC requirements but in everyday use it'll be acceptable.

Am I wrong in thinking Rolex doesn't make any highly-accurate movements? I know Bulova, Longines, Seiko, Omega and Citizen do.

I don’t use my watches to tell time so don’t even bother setting / syncing them precisely most of the time. Whilst I can appreciate the technical ingenuity required for precise timekeeping, on a practical level I am just not fussed if they are a little out


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I used to think it was a mark of accuracy but have found out it's pretty much meaningless in real terms, my COSC certified Tudor keeps worse time than a $50 Seagull, I consider it to be a marketing term mostly

Whether a watch us COSC rated or not, it must be regulated correctly.

I wouldn't wear an automatic without COSC(because I do use my watch to tell the time) so it's either the 16613 or a Seamaster in daily use. BUT there is one exception to the rule and that is an Orange Monster.

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Originally Posted by K300

I wouldn't wear an automatic without COSC(because I do use my watch to tell the time) so it's either the 16613 or a Seamaster in daily use. BUT there is one exception to the rule and that is an Orange Monster.

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So you wouldn’t be happy with my 1950s Seamaster bumper automatic that keeps tome to around 3-4 secs/ day but doesn’t meet COSC? I think you’re confusing a watch that keeps time to within a few secs/ day with COSC......two different things!

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Originally Posted by hafle

OK, so buying new it's a guarantee that the watch will run at a certain spec. But beyond that?

Recently sent my newmark 71 off to Brendan (Webwatchmaker) to get the bezel swapped out, and figured I'd throw my omega mk40 triple date in the box and have him regulate it.

It's not a watch that omega thought could or should get COSC certification, yet upon getting it back from Brendan a few days later, its running at +1s a day. Exactly what I'd asked if he could manage (the mk40 is a PITA to set the time).

Pretty damned pleased. Goes to show that certification isn't in itself proof of a watches superiority over another or should be seen to be of added value. Interestingly that, and the newmark, are by far my most accurate watches. No fancy certificates, just some folk who pay attention to doing things right.

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Consistency is more important that how many seconds a watch gain or lose.



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Doesn't mean anything to me. I've had watches from Eddie, Seiko and other brands that have run consistently within COSC spec which always made me wonder why the premium cost for those with a certificate? I've bought 'vintage' pieces from TZ members that have run +1 spd after they've regulated them so no, it doesn't mean jack to me.

It's not a big deal to me. I've bought a few new COSC watches & only once got a certificate - from Bremont as I recall.

Couldn't care less.

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Originally Posted by P9CLY

Doesn't concern me,my life isn't ruled to the hour or even seconds.Some people put too much importance on things that aren't important at all!.

Now if my heart wasn't ticking correctly,I'd have that regulated........

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:smug:+1 - and I did.

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Originally Posted by walkerwek1958

Whether a watch us COSC rated or not, it must be regulated correctly.

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I think this is the most important aspect, though companies like Omega do go further with METAS.

It means nothing to me... Maybe in the past it was different, but nowadays...

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Originally Posted by walkerwek1958

So you wouldn’t be happy with my 1950s Seamaster bumper automatic that keeps tome to around 3-4 secs/ day but doesn’t meet COSC? I think you’re confusing a watch that keeps time to within a few secs/ day with COSC......two different things!

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You're right I am so I'll modify my statement, a mechanical watch for me has to be keeping very good time say within 1 or 2 seconds a day or capable of it over a period of say 4-5 years.
How would you warranty that for me?