Sinn should know better: 10 bars does not correspond to a depth of 100 meters ....

May 11, 2019,08:39 AM
 

... since the air pressure on the sea surface already is 1 bar. So 10 bar corresponds to a depth of 90 meters, not 100. It is typical for so many erranous information given areound water tightness. The pressure resistance rating for a specific case is given for the time of production, similar to the chronometer certificate, that also is a report about a movement's performance at the time of testing. Depending on time and storage conditions, the pressure resistance can change, if the gaskets are degraded, for example for years in a shop window in bright sunshine and directly under hot halogen spotlights.The manufacturer cannot be held responsible for such a folly.

Additionally, experience shows that the average watch wearer (which excludes the crazy watch nut that is the rule on sites like PuristSPro) does not spend any thought on keeping his or her watch serviced and in good condition. These watches are seeing a watchmaker when they fail, and not earlier. Give them 100 meters of water resistance, and they believe that to be valid for decades, without any replacement of gaskets. Just ask a good watchmaker how many sports watches, including Rolexes, with completely corroded movements, caused by water immersion, they had on their tables. I am sure they will have plenty to tell. Consequently, I see a tendence to downscale the pressure resistance rating, jut not to be made responsible for any user-initiated humidity problem. Just an example: When I bought my first expensive mechanical watch, this was a Zenith chrono, then called Class 4, later Class El Primero. This had shaped pushers, a non-screw down crown and a snapback, all features normally not connected with high water resistance. Nevertheless, it was rated to 100 meters:



A bit later, the very same watch, without any constructional changes, was rated to 50 meters only. Apparently, it were legal considerations rather than technical ones that caused that change.

On the other hand, Ulysse Nardin was the first manufacturer rating its watches with repetition to 30 meters, while all others did not give any water tightness rating, due to the slider used for releasing the chimes. Apparently, they trusted their construction enough.

A different example of a non-understandable depth rating is the Seiko Marinemaster 300, featuring a massive monocoque case and tiny crystal diameter, which normally would indicate a depth rating in the four digit range, and officially offers only 300 meters. Apparently, it should be able to withstand much higher pressures, but the manufacturer does not want to risk any claims resulting from failure at high pressure situations. And, to be honest, even after degrading of the gaskets, the Marinemaster should withstand a 300 meter water column anytime.

A different approach is the regulation of the warranty. Whhile modern movements often get a longer warranty, period, its validity is connected to the condition of a regular water tightness test at the manufacturer's service center. Sometimes, this condition is barely mentioned before the purchase. Breitling, for example, gives 5 years warranty for all B1-equipped chronographs, but only, if the watch is sent in for water tightness testing every two years. If you buy such a timepiece pre-owned, without proof of that testing, you only have two years warranty from original purchase. Omega, in the opposite, does not demand such a testing and gives a prolonged warranty.

Marcus



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Here we go again...water resistance

 
 By: sc16 : May 11th, 2019-04:22
of a watch. I need, yes need, to get a better understanding of water resistance of watches and specifically screw down crown vs non screw down crown and 50 mtr and 100 mtr. I wanted a every day watch that i could take with me in the pool, perhaps a couple...  

From my Seiko manual

 
 By: Denes_Papp : May 11th, 2019-04:37
You do not have to have a screw down crown for swimming in a pool. You do ned a screw down crown for diving though. ...  

Thanks for this...

 
 By: sc16 : May 11th, 2019-04:46
Didn’t occur to me to check the manual and proves my point that my thoughts are correct. However, then why did the AD where i initially wanted to buy the strap said not recommendable for this watch and also that Seiko would no longer uphold the warranty i... 

Your AD is an idiot!

 
 By: Boron : May 11th, 2019-06:32
If a watch is water resistant to 100m, then it’s water resistant to 100m... no ifs, ands, or buts about it. What prevents water getting in are the seals in the crown tube, and as long as they’ve not degraded, then they will keep the pressurised water at b... 

That's what I thought....

 
 By: sc16 : May 21st, 2019-02:05
considering some of the other replies - will need to take the seals into consideration for sure and having them checked.

Please give me more details from that strap 🙏🏻

 
 By: Watchonthewrists : May 11th, 2019-05:23
It looks amazing on the Seiko and would love to have a blue one on my shippo 🤗

I had dropped you a pm,

 
 By: sc16 : May 21st, 2019-02:11
did you receive it?

Here's the ISO standard for water resistance

 
 By: cazalea : May 11th, 2019-07:38
Cazalea Opinion, explained for 5-year old - don't go in the water with a watch on unless it's a dive watch. Seiko Opinion: expressed as a chart SINN opinion: In order to use a watch safely when swimming we recommend a compression resistance of at least 10...  

Hear, hear! 10bar is a comfort when dashing to a parking spot in a rainstorm, and that's about it. And a point not yet mentioned...

 
 By: halgedahl : May 11th, 2019-08:05
On the whole, dive watches are much less expensive (the Nautilus, Blancpain 50, etc. obviously excepted) , there are gazillions of styles, and one or two might pleasantly enlarge the aesthetic of your collection. Have you ever really seriously looked into... 

Thanks for the alternative...

 
 By: sc16 : May 21st, 2019-02:12
No, I haven;t looked at one just yet...saw the longines legend (but if i would pursue it it would be the version without date) - I think that I am not yet ready for it, but perhaps in the future.

Like myself! Ha! I don't own one either! And I agree—despite having been tempted by the Seiko—that a date is obviously not necessary for the diver!

 
 By: halgedahl : May 21st, 2019-08:13
It's only there to make the watch more wearable as an everyday piece. Well… good to muse with you!

Sinn should know better: 10 bars does not correspond to a depth of 100 meters ....

 
 By: Marcus Hanke : May 11th, 2019-08:39
... since the air pressure on the sea surface already is 1 bar. So 10 bar corresponds to a depth of 90 meters, not 100. It is typical for so many erranous information given areound water tightness. The pressure resistance rating for a specific case is giv...  

Specs can be governed by marketing and legal, rather than engineering

 
 By: cazalea : May 11th, 2019-09:26
This situation reminds me of a conversation I had with the then-head of service for M-B in the US. As I was assembling the specs for maintenance for M-B passenger cars in our reference charts, I asked why the oil change interval was 20,000 km (~12,000 mi)... 

Sinn’s not all that wrong...

 
 By: Boron : May 11th, 2019-17:11
... just rounding up to the nearest whole number. Air pressure on the surface has zero effect on water resistance when submerged, since it’s not Hydrostatic pressure. Therefore, at a depth of 100m, the Hdyrostatic pressure is exerting a force of 9.81 bar,... 

the 5 year old explanation...

 
 By: sc16 : May 21st, 2019-02:11
makes sense and i understand...thanks for that

The irony is...

 
 By: Emile : May 11th, 2019-08:44
That the watch I use as my dive computer is a Garmin MK1 Descent which is rated at 100m and my sea dweller is rated 1200m. I'm a recreational diver and I have the basic PADI certification which allows you to go down to ~20m. If/when I want to go see somet... 

I don'd dive...

 
 By: sc16 : May 21st, 2019-02:14
it was more related to sitting and relaxing in the pool and then perhaps a couple of strokes to go from one end to the other (short end not the long one). I understand gaskest/ seals are the most important factor to weigh in, other than the manufacturers ...