How water resistant is the GMT Master II

[BLNR Nairobi]

Originally Posted by tyler1980

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.

[morimotom]

Originally Posted by 037

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.

[gliderpilot]

As a PADI dive master, I can say that virtually no one uses dive tables + watch for dive planning anymore. It is not only inconvenient, but inaccurate too. The computer knows how much air was consumed at what depth and can monitor the dive much better as a result.

That being said, I have taken my GMT2c 40m deep without hesitation on multiple occasions, mostly because there was no better place to put it on a sketchy dive boat.

In fact, if I see someone wearing a dive watch instead of having a computer, I inevitably ask a few saturation questions. 90% of the time the answers are not even ballpark correct, because the dive watch is more a fashion statement than anything else.

[Amochosto]

Originally Posted by gliderpilot

As a PADI dive master, I can say that virtually no one uses dive tables + watch for dive planning anymore. It is not only inconvenient, but inaccurate too. The computer knows how much air was consumed at what depth and can monitor the dive much better as a result.

That being said, I have taken my GMT2c 40m deep without hesitation on multiple occasions, mostly because there was no better place to put it on a sketchy dive boat.

In fact, if I see someone wearing a dive watch instead of having a computer, I inevitably ask a few saturation questions. 90% of the time the answers are not even ballpark correct, because the dive watch is more a fashion statement than anything else.

The answer

[donq]

I have taken my almost 20 year old Sub diving down to about 140 ft. Not so much that I needed it, but because it was fun and when I look at it, I can remember close encounters with sea turtles off Barbados and barracudas off Key Largo!

No one needs a dive watch anymore, but they are fun to take along.

[MARGARITATIME]

Not a diver. More like a desk diver and use BLNR so I can tell what time its in India. Very informative thread - like the picture of the twin vs triple lock designs. If I every get into Scuba (I think about the something about Polly movie) I would either use my Sub or a less expensive diver. Good to know though my BLNR can go deeper than I can hold my breath and I can swim without hesitation.

[Joemck]

Originally Posted by gliderpilot

As a PADI dive master, I can say that virtually no one uses dive tables + watch for dive planning anymore. It is not only inconvenient, but inaccurate too. The computer knows how much air was consumed at what depth and can monitor the dive much better as a result.

That being said, I have taken my GMT2c 40m deep without hesitation on multiple occasions, mostly because there was no better place to put it on a sketchy dive boat.

In fact, if I see someone wearing a dive watch instead of having a computer, I inevitably ask a few saturation questions. 90% of the time the answers are not even ballpark correct, because the dive watch is more a fashion statement than anything else.

Good for you. You can trip up a novice diver. I’m a novice diver but if you pulled that on me, I’d clock you. An overreaction to be sure but I resent the presumption that anyone over than a master diver who wears a sub is a poser. There is a middle ground. I’ve been in oceans, rivers, ponds ands pools for the past 54 yrs. I swam competively in high school & college and continue to swim several times a week now. Further, the history of the watch and the technological breakthroughs remain a wonder to me. I wear it as I can go from work to the pool or beach without concern. It is my favorite timepiece bar none( little bit of a pun for you ). Whether it’s worn as a dive tool or for swimming or just it’s history, for many here, it is not another piece of jewelry. The watch is loved for both what it represents and what it does. Rant over. I understand that any nitwit with money can buy a sub and you appear to have encountered more than your share. Sorry for your troubles.

[CRM114]

Originally Posted by Joemck

Good for you. You can trip up a novice diver. I’m a novice diver but if you pulled that on me, I’d clock you. An overreaction to be sure but I resent the presumption that anyone over than a master diver who wears a sub is a poser. There is a middle ground. I’ve been in oceans, rivers, ponds ands pools for the past 54 yrs. I swam competively in high school & college and continue to swim several times a week now. Further, the history of the watch and the technological breakthroughs remain a wonder to me. I wear it as I can go from work to the pool or beach without concern. It is my favorite timepiece bar none( little bit of a pun for you ). Whether it’s worn as a dive tool or for swimming or just it’s history, for many here, it is not another piece of jewelry. The watch is loved for both what it represents and what it does. Rant over

Seems the real difference between GMTs and Subs is if a Flight Instructor asks novice pilot a question about aerodynamics their reaction is to hit the books, not the instructor's face.

Question: Does all this clocking happen underwater? The reason I'm asking is because like at 45,000' and 500 kts in a pressurized tube above the surface and given that clocking someone easily (predictably!) leads to counter-clocking, grappling, and even drawing dive knives if you happen to have one handy, it seems with all those exposed air-hoses, masks, and regulators to grab, yank, or slice away, below the water's surface is also a rather unforgiving environment for hothead rough-housing. I guess we now know why some never make it back up to the surface. It wasn't sharks or giant squids or a...ahem, speargun "accident"...after all.

Diving with triggered Sub-wearers must be super exciting.

[gliderpilot]

Originally Posted by Joemck

Good for you. You can trip up a novice diver. I’m a novice diver but if you pulled that on me, I’d clock you. An overreaction to be sure but I resent the presumption that anyone over than a master diver who wears a sub is a poser. There is a middle ground. I’ve been in oceans, rivers, ponds ands pools for the past 54 yrs. I swam competively in high school & college and continue to swim several times a week now. Further, the history of the watch and the technological breakthroughs remain a wonder to me. I wear it as I can go from work to the pool or beach without concern. It is my favorite timepiece bar none( little bit of a pun for you ). Whether it’s worn as a dive tool or for swimming or just it’s history, for many here, it is not another piece of jewelry. The watch is loved for both what it represents and what it does. Rant over. I understand that any nitwit with money can buy a sub and you appear to have encountered more than your share. Sorry for your troubles.

LOL, anyone can of course dive with as many watches as they wish ;-)

Since keeping people alive tends to be my responsibility, people that dive with a watch INSTEAD of a computer need to have a good grasp of what they are doing because they will be receiving no warnings about required air margins for safety stops, etc.

No one was ever angry with me for checking on their safety, so you would be first :-)

But this thread is more about whether the GMT II is waterproof enough to handle recreational water sports. Yes it is, and it can handle recreational scuba diving just as well as the SubC.

[gliderpilot]

Originally Posted by CRM114

Seems the real difference between GMTs and Subs is if a Flight Instructor asks novice pilot a question about aerodynamics their reaction is to hit the books, not the instructor's face.

Question: Does all this clocking happen underwater? The reason I'm asking is because like at 45,000' at 500 kts in a pressurized tube, clocking someone leads to counter-clocking, grappling, and even drawn dive knives and it seems with all those exposed air-hoses and masks and regulators to grab or slice away it's a rather unforgiving environment for hothead rough-housing. Now we know why some never make it back to the surface. It wasn't sharks or giant squids or a...ahem, speargun "accident"...after all.

Diving with triggered Sub-wearers must be super exciting.

[NIHO]

Originally Posted by gliderpilot

LOL, anyone can of course dive with as many watches as they wish ;-)

Since keeping people alive tends to be my responsibility, people that dive with a watch INSTEAD of a computer need to have a good grasp of what they are doing because they will be receiving no warnings about required air margins for safety stops, etc.

No one was ever angry with me for checking on their safety, so you would be first :-)

But this thread is more about whether the GMT II is waterproof enough to handle recreational water sports. Yes it is, and it can handle recreational scuba diving just as well as the SubC.

Thank you all for your thoughtful replies. I especially appreciate those whose comments come from personal experience diving with GMTs.

[Joemck]

Originally Posted by CRM114

Seems the real difference between GMTs and Subs is if a Flight Instructor asks novice pilot a question about aerodynamics their reaction is to hit the books, not the instructor's face.

Question: Does all this clocking happen underwater? The reason I'm asking is because like at 45,000' and 500 kts in a pressurized tube above the surface and given that clocking someone easily (predictably!) leads to counter-clocking, grappling, and even drawing dive knives if you happen to have one handy, it seems with all those exposed air-hoses, masks, and regulators to grab, yank, or slice away, below the surface is also a rather unforgiving environment for hothead rough-housing. I guess we now know why some never make it back up to the surface. It wasn't sharks or giant squids or a...ahem, speargun "accident"...after all.

Diving with triggered Sub-wearers must be super exciting.

Well one can only hope...if you can’t recreate an episode of journey to the bottom it the sea, then it’s been a lackluster effort

[Joemck]

Originally Posted by gliderpilot

LOL, anyone can of course dive with as many watches as they wish ;-)

Since keeping people alive tends to be my responsibility, people that dive with a watch INSTEAD of a computer need to have a good grasp of what they are doing because they will be receiving no warnings about required air margins for safety stops, etc.

No one was ever angry with me for checking on their safety, so you would be first :-)

But this thread is more about whether the GMT II is waterproof enough to handle recreational water sports. Yes it is, and it can handle recreational scuba diving just as well as the SubC.

Not that angry & noted that I was overreacting. Usually I’m diving with a master diver as a buddy and he’s running the show. I have not picked up a dive computer but I’m not down more than 60 feet. The time is limited and that’s the dive for the weekend. The objection was to the perception on the forum that subs r purchased just for show with no appreciation for their history. You were just the unlucky guy to say it last, when I’m coming off knee surgery and watching the bruins lose. And I’m not saying that you don’t have a point. Just that the generalization implied doesn’t hold water. If you come to cape cod this summer, let me know & I’ll buy you a beer

[Watch Admirer]

Enough

[CRM114]

Originally Posted by Joemck

Well one can only hope...if you can’t recreate an episode of journey to the bottom it the sea, then it’s been a lackluster effort

All I know is the only way I'd go diving is if I'm the only one down there with a bang stick.

[gliderpilot]

Originally Posted by Joemck

Not that angry & noted that I was overreacting. Usually I’m diving with a master diver as a buddy and he’s running the show. I have not picked up a dive computer but I’m not down more than 60 feet. The time is limited and that’s the dive for the weekend. The objection was to the perception on the forum that subs r purchased just for show with no appreciation for their history. You were just the unlucky guy to say it last, when I’m coming off knee surgery and watching the bruins lose. And I’m not saying that you don’t have a point. Just that the generalization implied doesn’t hold water. If you come to cape cod this summer, let me know & I’ll buy you a beer

I hear you. Interestingly, it is not the Sub owners that I am worried about as they typically fall into a fairly intelligent demographic. The red light goes on when a person with a massive diver watch and a Rambo style knife strapped to his leg struggles with basic gear assembly ;-)

BTW, I started diving before computers were a thing and really appreciate if someone knows how to dive without them, old-school. Unfortunately, it happens less and less...
(curious how many dive watch owners know why the first 15min are marked differently on the bezel)

But more importantly, all the best with your knee recovery!!!

[Dirt]

Originally Posted by zjd168

Rolex claims testing 25% beyond the depth printed

No.
Actually, it's +10% for the GMT along with all other Rolex watches.
With the distinct exception of their Dive watches, which are indeed +25%.

[Andad]

Originally Posted by Lo100169

50 bar not 500.....

No I meant 500 Bar.
This pressure resistance, for the Triplock with the crown unscrewed, was stated on the Rolex website around 2008.

The Rolex DSSD is rated to 390 Bar.
Add in a safety margin and even that sort of shoots down your 50 Bar.

You need to do some research before posting as few on this thread have done.

[Andad]

Originally Posted by gliderpilot

I hear you. Interestingly, it is not the Sub owners that I am worried about as they typically fall into a fairly intelligent demographic. The red light goes on when a person with a massive diver watch and a Rambo style knife strapped to his leg struggles with basic gear assembly ;-)

BTW, I started diving before computers were a thing and really appreciate if someone knows how to dive without them, old-school. Unfortunately, it happens less and less...
(curious how many dive watch owners know why the first 15min are marked differently on the bezel)

But more importantly, all the best with your knee recovery!!!

Curious that not many know that for a watch to pass ISO 6425 and meet the requirement to be called a 'diver' the dial must be coordinated with those on the pre-selecting device, and the bezel shall have graduations at every minute marker and at every five minutes.

A bezel with only the first 15 minutes marked does not meet this Standard.

Note that the new SD has the correct markings on the bezel so Rolex have caught up.

[tyler1980]

Originally Posted by gliderpilot

As a PADI dive master, I can say that virtually no one uses dive tables + watch for dive planning anymore. It is not only inconvenient, but inaccurate too. The computer knows how much air was consumed at what depth and can monitor the dive much better as a result.

That being said, I have taken my GMT2c 40m deep without hesitation on multiple occasions, mostly because there was no better place to put it on a sketchy dive boat.

In fact, if I see someone wearing a dive watch instead of having a computer, I inevitably ask a few saturation questions. 90% of the time the answers are not even ballpark correct, because the dive watch is more a fashion statement than anything else.

ive only ever been to 40M once . I had trouble functioning at anything past 30. Part of my Advanced Certification was to go to 40M and then try to carry out simple tasks. Its harder to do than carrying out similar activities after 8 shots of whiskey. So its not even an issue to almost anyone as any deeper I would need to dive with nitrox and im not even certified for that.

[Gunbucker]

National Geographic's Dr Sylvia Earle dives with her Datejust. Enough said.

https://www.hodinkee.com/articles/di...spatches-rolex

[HogwldFLTR]

My neighbor bought his GMT under the impression it was a Dive watch; he's been using it as such for 30+ years.

[Mystro]

Originally Posted by Gunbucker

National Geographic's Dr Sylvia Earle dives with her Datejust. Enough said.

https://www.hodinkee.com/articles/di...spatches-rolex

^^^^^^Great read.

[gliderpilot]

Originally Posted by tyler1980

ive only ever been to 40M once . I had trouble functioning at anything past 30. Part of my Advanced Certification was to go to 40M and then try to carry out simple tasks. Its harder to do than carrying out similar activities after 8 shots of whiskey. So its not even an issue to almost anyone as any deeper I would need to dive with nitrox and im not even certified for that.

Interesting point. This is the main reason why the GMT is not suitable as a dive watch. Since cognitive functions are affected by nitrogen, the end of dive needs to be marked very clearly on a uni-directional bezel, to avoid any confusion. Relying solely on your memory or math skills to do time calculations at depth could be dangerous ;-)

Some dive watches even mark the "overtime" red on the bezel, have a very pronounced minute hand, luminous marker on the bezel, different lume on the minute hand, etc.

This is all regulated by ISO 6425 and the Rolex GMT is definitely not a dive watch by these standards. But it surely is build more than well enough to handle the ambient pressure experienced while diving recreationally :-)

[Speedbird-1]

Originally Posted by CRM114

Seems the real difference between GMTs and Subs is if a Flight Instructor asks novice pilot a question about aerodynamics their reaction is to hit the books, not the instructor's face.

Question: Does all this clocking happen underwater? The reason I'm asking is because like at 45,000' and 500 kts in a pressurized tube above the surface and given that clocking someone easily (predictably!) leads to counter-clocking, grappling, and even drawing dive knives if you happen to have one handy, it seems with all those exposed air-hoses, masks, and regulators to grab, yank, or slice away, below the water's surface is also a rather unforgiving environment for hothead rough-housing. I guess we now know why some never make it back up to the surface. It wasn't sharks or giant squids or a...ahem, speargun "accident"...after all.

Diving with triggered Sub-wearers must be super exciting.

Lovely
My kind of humour, excellent !

I think we can see the granite jawed, stern faced response, "diving is a serious business"!

[Joemck]

Originally Posted by gliderpilot

I hear you. Interestingly, it is not the Sub owners that I am worried about as they typically fall into a fairly intelligent demographic. The red light goes on when a person with a massive diver watch and a Rambo style knife strapped to his leg struggles with basic gear assembly ;-)

BTW, I started diving before computers were a thing and really appreciate if someone knows how to dive without them, old-school. Unfortunately, it happens less and less...
(curious how many dive watch owners know why the first 15min are marked differently on the bezel)

But more importantly, all the best with your knee recovery!!!

Thanks! Appreciate it! My dive instructor had his fair share of war stories about nit wits with combat knives or one couple that had nails protruding out of a wooden pole( apparently they had trouble submerging with their ‘weapon.’)
Good stuff

[904VT]

Originally Posted by Tools

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.

Great overview you gave years ago linked here

https://www.rolexforums.com/showthread.php?t=87780

[ganagati]

Originally Posted by 904VT

Great overview you gave years ago linked here

https://www.rolexforums.com/showthread.php?t=87780

I wonder how different the current Master II would be...