How water resistant is the GMT Master II

[morimotom]

Originally Posted by tyler1980

so what you are saying then is the original submariner was not a dive watch at 100M WR. Or for that matter the original dive watch the BP 50 Fathoms? 50 Fathoms is 91.45m.

I think that about sums it up

I didn’t make this up, so no, it isn’t me saying this. I don’t know how Rolex rated the original sub, but according to many sources this is how watches are rated/tested today. Tech changes and advances, as do capabilities of manufacturers and their products.

If you can explain why this is so and cite a reliable source I would be happy to read it.

[morimotom]

Originally Posted by donq

Jack Forster did a good article discussing this..

https://www.hodinkee.com/articles/wh...can-trust-them

This is worth reading as well.

http://forums.watchuseek.com/f2/sigh.../topics/610734

Interesting. Articles.

[Lo100169]

Originally Posted by directioneng

Forgot to mention that on the Rolex website the Triplock was described as rated to 500 Bar even when the crown was unscrewed.
The finger tight crown doesn't seem to do much.

50 bar not 500.....

[037]

Originally Posted by morimotom

If you can explain why this is so and cite a reliable source I would be happy to read it.

Even Suunto dive computers are "only" rated between 80M and 200M. They're by far the most popular dive watch for professional and commercial divers. If these numbers weren't good enough then dive computers would be made like the DSSD. But, they aren't because it's not necessary.

The problem with these online articles is that they're authored by writers who aren't professional mechanical engineers with high-pressure valve and seal experience. It's easy to read a few manufacturer specs and conjure up an article that sounds good to the masses and makes for good clickbait ad revenue. Conversely, if the source actually provides engineering data and test results, then it might be worth the time.

[zjd168]

Rolex claims testing 25% beyond the depth printed

[Tools]

Originally Posted by NIHO

Is anyone aware of any "aftermarket" testing on the GMT IIc maxi-case. I know it is only officially rated to 100m, but with the trip lock crown I am guessing it is much better. Has anyone tested this in a chamber to see "how low it will go"?

You have fallen into a common trap. Just because it has a Trip-lock crown, that doesn't make it "Sub" comparable. The crown is not the weak-link.

There is a lot more that goes into a waterproof rating, but the biggest difference here is the relatively thin case back on the GMT that will crush into the movement at depth.

A good Twin-loc crown isn't going to let any water in either and would not likely fail before the other seals.

[Rashid.bk]

Originally Posted by morimotom

I consider this reliable.

https://www.thrillist.com/gear/what-...e-numbers-mean

Similar info from different sources, and I have seen this several other places. Theo&Harris posted a video the other day on this topic, and is consistent with these sources.

That list makes no sense, honestly. The only thing considered a dive watch is something with a 300m water resistance? I call BS, sorry.

Originally Posted by directioneng

Rolex watches are rated to actual depth and are tested to those depth pressures.

100m = 100m

300m = 300m

4000ft = 4000ft

etc.

This makes it easier to understand.

This does make sense, and what I'd bet on.

[Onikage]

Originally Posted by 037

Here's an engineering drawing of the three o-rings and sealing washer. Even without calculating pressure via cross-section, I'd believe 500 BAR without much question. It's a similar design to many high-pressure steam valves rated to 5000+ PSI. 500 BAR is 7350 PSI.

It's missing the all-important triplock o-ring though.

[SeaAndSky]

Originally Posted by Watch This

Beyond anything you would likely require of it.

This. 300 feet is very deep. If you’re at that depth you’re probably trapped in sinking boat and time won’t be a concern of yours for too much longer. If you want to be assured your caseback can go deeper get a Sub variant.

[037]

Originally Posted by Onikage

It's missing the all-important triplock o-ring though.

You're right. That was a 701 drawing, not a 703. Still a Triplock but not the latest revision. Either way it's still one heck of a labyrinth seal.

[beshannon]

Just wore it in Jamaica scuba diving. Was down 26 feet with no issues.

[Onikage]

Originally Posted by 037

You're right. That was a 701 drawing, not a 703. Still a Triplock but not the latest revision. Either way it's still one heck of a seal.

Absence of the visible triplock o-ring in the crown tube threads makes it a Twinlock as far as I know.

[037]

Originally Posted by Onikage

Absence of the visible triplock o-ring in the crown tube threads makes it a Twinlock as far as I know.

No, the Twinlock is a different design. It's not the number of o-rings but how everything threads together that makes the major differences. The Twinlock crown is much smaller.

What I posted is correct, just not recent.

[Onikage]

Originally Posted by 037

No, the Twinlock is a different design.

Oh. Ok! I learnt something today.

[Hoppyjr]

Originally Posted by Onikage

Absence of the visible triplock o-ring in the crown tube threads makes it a Twinlock as far as I know.

Nope. There is the original Triplock and the revised one that we associate with the external o-ring.

The Pelagos uses the older style Triplock, as confirmed by RSC Dallas.

[037]

Originally Posted by Onikage

Oh. Ok! I learnt something today.

Sure thing.

This isn't the best photo but the first decent one I found online:

[Onikage]

Informative stuff. So there is no seal on the inside of the crown on a Triplock with the visible o-ring? The fingertight crown thing really is next to pointless? Kidding. It seems the external o-ring takes the place of the inner crown seal on the Twinlock. I did not know that.

[Fabrice M]

It doesn’t really matter, 95% of people dive between 15 to 30 ft. The main reason is it’s safer, most of the cool stuff is between 20-30ft, no much need to go lower and most rental tank are 80cu ft, which means 1/2 to 45 mn depending on your experience and no decompression stops necessary, although a couple of mn at 10 ft is always a good idea for beginners . At 50ft, you have to do a stop, and it can take a while to get there if you aren’t used to it. Most people will get a bottom time of around 10-15mn and then you have to go up and make sure you have enough air for one décompression stop. 100ft / 33m, it’s dark, not much to see in most places, you need multiple tank, at this point you are a technical diver, a tiny percentage of divers and you rely mostly on your computers ( main and back-up when necessary...

Anyway, a GMT would do fine at any of those depth.... And if you go deeper that this, chance are your are not a GMT guy.

[morimotom]

Originally Posted by Rashid.bk

That list makes no sense, honestly. The only thing considered a dive watch is something with a 300m water resistance? I call BS, sorry.



This does make sense, and what I'd bet on.

I’m not the author, so call whatever you like. I can either believe forumites who have opinions (based on what? Idk) or the opinions of authors of other publications.

I wouldn’t want to be a test case with my GMT just to see if it’s ok to dive with. Since my exposure to water is limited to swimming pools, at least whilst wearing a watch, none of it really affects me personally anyway. I haven’t scuba dived in like 20 years.

What I also won’t do is patronize someone who suggests an opinion opposite my own ( not directed at you Rashid, just a general attitude that often shows up in this forum).

[morimotom]

Originally Posted by 037

Even Suunto dive computers are "only" rated between 80M and 200M. They're by far the most popular dive watch for professional and commercial divers. If these numbers weren't good enough then dive computers would be made like the DSSD. But, they aren't because it's not necessary.

The problem with these online articles is that they're authored by writers who aren't professional mechanical engineers with high-pressure valve and seal experience. It's easy to read a few manufacturer specs and conjure up an article that sounds good to the masses and makes for good clickbait ad revenue. Conversely, if the source actually provides engineering data and test results, then it might be worth the time.

Do we consider dive computers and watches to be in the same category?

Are they tested the same? Does a dive computer, with no moving parts, require a different type of testing/rating?

I don’t know.

[Scott.sanders]

Took my BLNR down to 20m in both Jamaica and Cozumel this past week. That’s the extent of my definitive knowledge! Hope it helps someone.

[jimcameron]

I enjoy the discussion about the capability of all dive watches vs. non-specific dive capable watches.

I can remember after a long ago dive in Key Largo, trying to dry out a Timex "dive watch" that had moisture in the case. Here's a tip; don't hang your Timex inside a lampshade in an effort to dry it out. My Timex melted into a hideous glob of plastic and metal.

As far as my current recreational diving, the 16800 stays home and my much, much cheaper version gets to go for a swim.

[donq]

Originally Posted by morimotom

I’m not the author, so call whatever you like. I can either believe forumites who have opinions (based on what? Idk) or the opinions of authors of other publications.

The author of this article is responsible for other hard hitting pieces such as:

All 50 State Mottos Ranked!
https://www.thrillist.com/culture/u-...-mottos-ranked

And

10 Ways you’re making Cofee Wrong

https://www.thrillist.com/vice/coffe...ve-your-coffee

Jack Forster (who’s article I provided a link to) has serious credentials as a writer about watches.

https://www.hodinkee.com/pages/masthead/53

I know who I would listen to. But hey it’s just a forum!

[lecorsaire]

The GMT is as good as a Sub for recreational diving. That’s just the truth. Keep in mind the modern machinery these watches are made with compared to the original Submariner. The precision is better than it has ever been. Those idiotic WR descriptions apply to lesser watches. This is Rolex not low-end Swatch group crap. When Rolex says 100m they mean 100m and even more. That’s more than enough for any recreational diver. Professional saturation divers are the only people who would need a Sub or SD. Even then, they will be using computers. These watches were useful decades ago but they’re obsolete for this purpose.

Today, luxury dive watches are really just for style. They’re a symbol of masculinity and adventure.

[Mystro]

For that matter, any oyster like a DJ is good for recreational snorkeling. I would take my DJ2 diving without worry if I was on vacation. I have met many over the years that dive with their DJ.

[morimotom]

Originally Posted by donq

The author of this article is responsible for other hard hitting pieces such as:

All 50 State Mottos Ranked!
https://www.thrillist.com/culture/u-...-mottos-ranked

And

10 Ways you’re making Cofee Wrong

https://www.thrillist.com/vice/coffe...ve-your-coffee

Jack Forster (who’s article I provided a link to) has serious credentials as a writer about watches.

https://www.hodinkee.com/pages/masthead/53

I know who I would listen to. But hey it’s just a forum!

Agree, the Hodinkee article is good.

[swils8610]

Is a frogs ass water tight?


Sent from my iPhone using Tapatalk Pro

[037]

Originally Posted by morimotom

Do we consider dive computers and watches to be in the same category?

Are they tested the same? Does a dive computer, with no moving parts, require a different type of testing/rating?

I don’t know.

Yes, the industry considers them in the same category and uses the same tests for depth and pressure rating. Diving standards are set because human lives are at stake whether it be a Navy welder performing ship repair at 30' or a commercial diver at 200'. Automatic watches of yesterday and dive computers of today have to survive in the exact same environments.

[037]

Originally Posted by swils8610

Is a frogs ass water tight?

Haven't heard that one in a while. Well done.

[tyler1980]

Originally Posted by donq

The author of this article is responsible for other hard hitting pieces such as:

All 50 State Mottos Ranked!
https://www.thrillist.com/culture/u-...-mottos-ranked

And

10 Ways you’re making Cofee Wrong

https://www.thrillist.com/vice/coffe...ve-your-coffee

Jack Forster (who’s article I provided a link to) has serious credentials as a writer about watches.

https://www.hodinkee.com/pages/masthead/53

I know who I would listen to. But hey it’s just a forum!

Buying bad coffee and screwing up the water to coffee ratio are two ways you are making coffee wrong... without brilliant insights like this i would be helpless to navigate the complex world of coffee.

I totally trust that guy to tell me which watch is safe to dive with.