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Do dive watches need ISO 6425 certification to be "true divers"?

38K views 155 replies 38 participants last post by  mxm 
#1 ·
Curious about this. The vast majority of divers out there have not undergone ISO 6425 testing, and hence do not have "proper" certification as a real diver watch. So would it be accurate to say that all divers that lack the ISO certification (regardless of its water resistance rating) aren't "real" divers, but rather are diver-styled watches with high water-resistance ratings?
 
#2 ·
unquestionably no, they do not.

Any of the boutique makers or reputable brands out their are producing true divers, in that they are watches which can be worn or used while diving. ISO cert or not, it's of very little interest to me.

I'm not sure how relevant the certification is anymore, when pretty much any company can design/order/assemble high quality dive watches. It's not really the sole domain of only a few brands anymore, only the ones who have 'the technology', like it was a couple decades ago.
 
#3 ·
Wikipedia, excellent (brief) summary of the first dive watches, includes ISO 6425 specs:

Diving watch - Wikipedia, the free encyclopedia

Of most interest to me is the spring-bar test, as I've lost (and fortunately recovered) more watches do to spring bar failure than any other problem.

Quote from above link:

ISO 6425 also provides minimum requirements for mechanical diver's watches (quartz and digital watches have slightly differing readability requirements) such as:

  • The presence of a unidirectional bezel with at least at every 5 minutes elapsed minute markings and a pre-select marker to mark a specific minute marking.
  • The presence of clearly distinguishable minute markings on the watch face.
  • Adequate readability/visibility at 25 cm (9.8 in) in total darkness.
  • The presence of an indication that the watch is running in total darkness. This is usually indicated by a running second hand with a luminous tip or tail.
  • Magnetic resistance. This is tested by 3 expositions to a direct current magnetic field of 4,800 A/m. The watch must keep its accuracy to ± 30 seconds/day as measured before the test despite the magnetic field.
  • Shock resistance. This is tested by two shocks (one on the 9 o'clock side, and one to the crystal and perpendicular to the face). The shock is usually delivered by a hard plastic hammer mounted as a pendulum, so as to deliver a measured amount of energy, specifically, a 3 kg hammer with an impact velocity of 4.43 m/s. The change in rate allowed is ± 60 seconds/day.
  • Chemical resistance. This is tested by immersion in a 30 g/l NaCl solution for 24 hours to test its rust resistance. This test water solution has a salinity comparable to normal seawater.
  • Strap/band solidity. This is tested by applying a force of 200 N (45 lb[SUB]f[/SUB]) to each spring bar (or attaching point) in opposite directions with no damage to the watch or attachment point.
  • The presence of an End Of Life (EOL) indicator on battery powered watches.
Testing diving watches for ISO 6425 compliance is voluntary and involves costs, so not every manufacturer present their watches for certification according to this standard.
 
#4 ·
No, it's not required but in reality there are a lot of divers that meet the ISO 6425 requirement even though they have not been tested. I believe even a Seiko Monster meets the requirements for example.
There are others like the Orient Beast for example that take it a step further and are tested for ISO shock resistance and anti-magnetic properties as well.
I can't remember the ISO numbers off the top of my head for those though.
 
#7 ·
No, it's not required but in reality there are a lot of divers that meet the ISO 6425 requirement even though they have not been tested. I believe even a Seiko Monster meets the requirements for example.
Actually, some Seiko Monsters are actually explicitly stated as being ISO 6425 compliant - this is shown by the text that states "Diver's 200M" rather than "Water Resistant 200M". But yes, so many watches are implicitly compliant as they meet all of the criteria, they just don't bother with being official about it.

As lexvil and kelt06's responses state, a lot of legitimate dive watches, like the ones they use when diving, are not officially ISO 6425 compliant. But the standard has almost been reverse engineered from the true dive watches of the past, like kelt06's Submariner.
 
#5 · (Edited)
Safe diving was carried out long before the ISO rule was implemented.

I have used a Submariner 5512 during all my active carreer from the 1970s until 2003, as a diving superintendant (AODC bell diving supervisor certificate) or as client's representative onboard a DSV (diving support vessel) I was supposed to check and that all Equipment and personnel were qualified for diving work within régulations local and international (North sea diving rules) and I was a stickler to the valid rules for offshore oïl commercial diving of witch the ISO 6425 1st produced in 1984 and revised in 1996 wasn't part.

My watch was not in accordance with ISO 6425.
 
#8 ·
The biggest problem with ISO 6425 is that the company self certifies compliance. There is no independent inspector who verifies the testing component is being done, so you could have two ISO 6425 watches that have been tested under different criteria (say one company tests 100% and another tests 2%).

Also, for whatever reason, many (most?) of the big players in the dive watch business don't say whether they comply, even though the probably do. Rolex for example tests their watches before and after the movement goes into the case.
 
#14 · (Edited)
The primary advantage to ISO 6425 certification is you know that particular watch has been tested. A watch company can make a "diver's"model which meets or exceeds the ISO standard and test a representative sample (e.g. 2% in the example above) and rightly (or wrongly) assume the rest of the batch is equally robust.
Then you have to rely on the brand's reputation. No one, indeed, is going to doubt a Rolex is up for a dive, and I'm sure the better microbrands are equally reliable, My understanding is some of the micros (Helson?) test each watch individually without the expense and trouble of ISO certification.
If you have an ISO 6425-certified watch you know the one you actually have on your wrist has been tested and passed. This includes thermal shock resistance testing
("Immersion of the watch in 30 cm of water at the following temperatures for 5 minutes each, 40 ºC, 5 ºC, and 40 ºC again, with the transition between temperatures not to exceed 1 minute.") so you don't have to worry about those treacherous showers and hot tubs.
Annual testing if you dive frequently is, of course, wise, but if your watch says 6425 you know it's at least been tested once.
 
#16 ·
...My understanding is some of the micros (Helson?) test each watch individually without the expense and trouble of ISO certification.
ISO 6425 is a standard, and testing it done by the manufacturer. There is no ISO 6425 certification.....
 
#17 · (Edited)
As stated above, there is no 'certification.' ISO 6425 is a standard. If you put "diver's", "diver's watch", "diving watch", or any similar markings on your watch, you are, as a manufacturer, implying the watch has been tested in accordance with ISO 6425. If you put such marking on the watch, and someone becomes aware that you do not, in fact, test according to the standard, you can be accused of false advertising.

In addition to the water proof tests (three different tests), there is the strap test, anti shock test, anti magnetism test and the thermal shock test.
 
#19 ·
So ISO 6425 is basically just a marketing gimmick? Also, would this mean that any diver watch not ISO-rated may not be anti-magnetic or temp. resistant? So it would be safer to presume that they are not anti-magnetic, etc, until tested as otherwise?
 
#18 ·
Thanks for the explanations. However, if ISO compliancy is not necessary for a watch to be a "diver", then are 100m water-resistant watches with timing bezels also considered "divers"? (Seiko 100m dive watches are an example.) I guess my confusion lies in the fact that there is supposedly a difference between "diver styled" and a "real diver" watch. Or is there no difference, and any watch can be called "diver's" so long as it doesn't leak, has a timing bezel, and functions properly during a dive expedition?
 
#21 · (Edited)
yes, they are.

here is a pic of what can for all intents and purposes be considered a real dive watch:

Watch Analog watch Watch accessory Black Strap

It has a functioning bezel, 100m WR and is reliable to boot.

This, is a diver styled watch:

Watch Analog watch Watch accessory Fashion accessory Jewellery


cheap fleebay fodder in the shape of a dive watch. For all I know it might survive a swim, but I wouldn't rely on it.

Not maybe the best examples, but best I can find right now.

It really boils down to 'is it water resistant?' and if yes, 'is the claim reliable?' in the case of most known or boutique brands will be reliable. Very few manufacturers would put WR on the dial if they couldn't take a dip. Why would they, unless its to create problems for themselves everytime someone wore their watches in the rain or while washing the car. I have never had a new watch fail a dive, ranging from $25 cheapo's to $600 boutique brands. Buy the brand I guess, and the appropriate WR (100m is more than enough even for most divers)

This watch can be had for under $50 on evilbay, doesn't even have a specified WR. Yet recently a buddy showed up for a dive without a watch. I keep this rotary in my dive kit to lend out, and on his wrist it dove down to 15m repeatedly and in water hovering above freezing.

Watch Analog watch Watch accessory Fashion accessory Strap

not my pic.

This is the most suspect watch I've ever had in the water, and yet it did fine. It wasn't mine, I bought it for a buddy who liked it, I was a little doubtful of the WR claim, as the brand, um, image was obviously made up completely, and it just looked like a cheap fashion watch to me. cost $75. It was WR just fine until the friend smashed it on a concrete floor.
Watch Analog watch Watch accessory Black Strap


Basically I think the usual 'true dive watch' criteria you see talked about on forums are hype designed to make people think that spending less than 1k will not get you a real diver you can rely on, when the truth is that companies can produce reliably WR watches these days for chump change, the technology is old news, everyone can do it.
 
#24 ·
i had a chat with Robert Dreyfuss (owner/chairman of Rotary), he came by the shop i worked in at the time when we started selling Dreyfuss watches, to make sure we bought into the "story" they were telling if you could believe that.

he stated that rotary watches are designed to go as far down as a human can on one breath so they all carry a rating of 100m which they can achieve without a screw down crown. He also said that they put the screw down crown on their watches to put customers at ease as people wouldnt trust a 100m rating without screwing down the crown but with push down crowns these days they can make a 100m rating no problem.

so James's rotary is rated 100m yet it has a bezel and has survived 15m dives so really a dive watch for me is a watch that has a timing feature i.e a bezel and can regularly survive dives, any ISO rating doent really mean anything to me as long as im confident the brand can stand up to its WR claims.
 
#28 ·
JUST A NOTE:

There are "diver's watches", watches designed and tested for use by scuba divers, both professional, and leisure.

And, there are diver's watches (without the apostrophes), watches owned and used by scuba divers, both professional and leisure.

A "diver's watch" should be tested in accordance with ISO 6425 of similar standard (such as DIN 8306).

A diver's watch (without the apostrophes) can be anything, with any depth rating. I know a diver that owns a Saxonia, rated at 30 meters, if he feels safe diving with that, that's his business*. But, just because it is a diver's watch (owned and used by a diver), it is not necessarily a "diver's watch" (designed and tested for use during scuba diving).....

_____________________________
Don't worry, he doesn't....as far as I know.
 
#36 ·
Did a quick search "ISO 6425 Divers' watch" and found this beautiful watch w/ 3 ISO certs:

ORIENT M-FORCE EL03004B


SpecificationsMechanical Movement : ORIENT caliber 40N5A Made in Japan
Self-winding & Hand-winding movement
(Second Hand halt mechanism)
Enhanced shock proof
22 jewels
21,600/hour vibrations
Power reserve indicator, Date indicator

Stainless steel case and Rubber strap
One-way rotating bezel
Sapphire crystal
Screw caseback
Screwed-down crown
Diameter 46.00mm
Thickness 13.30mm
Water resistant to 200m
(Certificated by ISO 6425 diver' s watches, ISO 764 antimagnetic watches and ISO 1413 shock-resistant watches)
 
#38 ·
Read some of the comments in this previous thread.

https://www.watchuseek.com/f74/iso-certified-diver-576196.html

"ISO is totally worthless" #2 post

"...allow the manufacturer to put certain nomenclature on their product" #3 post

"If you're a diver and you've decided to forego the computer, and trust your life and safety to a watch, hopefully you already know what you need, and don't need ISO telling you otherwise. ISO deals with the idiot factor, and if you need ISO to hold your hand, then you don't need to be in the water." #5 post

"If you can buy a $150 dollar dive watch that is ISO certified, why buy a $1000 watch that isn't?" # 6 post

And so the proverbial question remains unanswered -- Should I be ISO compliant, Or, Should I Not Be ISO compliant.

Ultimately, do you trust your equipment and the persons who manufactured and stand behind it? Without knowing the manufacturer or their reputation, ISO seems to be a useful standard. Do any desk divers' watches really ever get tested to the depths stated on the dial? Probably not. But, this much I know -- if my 1,000m or 2,500m fails in the swimming pool, shower or river (not through my own fault), then I will be sending it back to who ever built it.

RHINO
 
#40 · (Edited)
That was a blast from the past. I think that thread was one of the very first I posted on WUS. The funny part for me was the end where I said I'd never wear an 8K Rolex because I'd be worried about losing it. Like many of us on here, my perspective has changed.

Not only that, I bought a Sub C about 9 months after saying I wouldn't. Damn glide lock did me in. On the bright side, I've never regretted it.
 
#43 ·
Do each and every Marathon get tested and must pass ISO 6425 due to it's under Gov. Contract or do they test at random.
One of the main differences between ISO 6425 (Diver's watches) and ISO 2281 (Water Resistant Watches) is ISO 6425 requires all watches to be tested to 125% their rated pressure.

ISO 2281 only requires a sample to be tested to 100% the rated pressure. And further, the sample size is determined by the manufacturer to satisfy his confidence level.

So, if manufacturer A makes WR watches to ISO 2281 and wants an extremely high confidence in the quality of their product he may set the sample rate at 50%. So every other watch is tested.

Manufacturer B also make WR watches to ISO 2281, but wants to save money, so he samples one watch one each batch of 1000 watches.

Both are in compliance with ISO 2281, but which watch would you rather have at the pool or in a dive?

Manufacturer C decides to make ISO 6425, "diver's watches" and test each and every one before shipping them off.

Now which watch would you rather have in the water?

If you see "Water Resistant" you have to ask yourself: "is this one of the watches tested, or was it just assembled and shipped?"

If you see "ISO 6425" or "diver's watch", you know this watch was tested to 125% the rated pressure, and passed, before it left the factory.

Of course, more testing means more cost, so the next thing you ask is, "How likely am I to get this wet?"
 
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#42 ·
I think I have new "I don't care so don't click it" categories
1. What is the biggest heaviest dive watch I can get
2. Anything to do with ISO (just moved up from the bottom of the list)
3. This or that or help me decide or recommend me a dive watch
4. what is the deepest depth rated watch
5. Anything "tactical"
6. I know there are more but I don't care enough to think them right now :-d
 
#46 ·
A dive watch that cannot fulfill the very basic ISO 6425 or its DIN equivalent, can still be called a dive watch in marketing terms, but technically this is the minimum set that every Professional dive watch should fulfill. Remember that this standard was published in 1982, so if a Professional dive watch cannot fulfill it 30 years later, using todays manufacturing technologies, then I wonder !!! BTW, every AQUADIVE except for the New Old Stock collectors models, exceed DIN 8306 by far, all tests are conducted by independent accredited institutes.
 
#70 ·
It would depend on the geometry of the vessel, a thick cylinder with hemispherical ends would have the least deformation. A low flat cup with flat ends would see the ends bow outward, how much would depend on the thickness.

I did a design study o this a few years back and came to the conclusion, if the inside is about 2.5 inches in diameter and about 3.5 inches long it will fit just about any watch and with the walls about 3/8 inch thick, the deflection will be negligible. Coincidently, that looks about the same size as the Lentz tester I pictured and the Roxers. (but, the Roxers are made from steel.)
 
#71 · (Edited)
The name of the Manufacturer of the tester you posted the pictures from is "LITITZ", difficult to read on the small front picture unless you know the brand.

Follow the link, and there is a video clip showing the use of their pressure tester and why the viewport is useful to check/remove air bubbles from the internal volume before clamping the cover; hence my comment above.

Lititz Precision Products | Quality Watch Testing Equipment
 
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