Why GMT IIc only rated to 100M

[mfer]

I'm looking at my sub. Says "1000ft=300m". Looking at the stats on my GMT IIc in the mail. Docs say good to 100m. It has the triple crown over the twin lock. Is the GMT IIc really good to 300m as well?

In the latest issue of WatchTime, they said that the DS was actually tested down to 15000ft, but Rolex chose 12,800ft instead.

[BigHat]

Originally Posted by mfer

I'm looking at my sub. Says "1000ft=300m". Looking at the stats on my GMT IIc in the mail. Docs say good to 100m. It has the triple crown over the twin lock. Is the GMT IIc really good to 300m as well?

In the latest issue of WatchTime, they said that the DS was actually tested down to 15000ft, but Rolex chose 12,800ft instead.

Good thread on this awhile back. We established with the help of many that the crystals are the same as the Sub. Of course, both have triple lock crowns. The great unknown is the caseback.

A pure guess on my part -- want that to be clear -- is that the Sub and GMT-IIC are much closer together on water resistance than they are rated. 1) it could be a marketing effort to impress the "Lloyd Bridges" types to opt for the Sub. I mean, that's about the only "plus" feature of the Sub over the GMT. 2) it just be keeping with the rating of the GMT-II to avoid undercutting the reputation of the remaining inventory.

To your last point -- Rolex tests "past" specs in insure the specs are attained in practice.

[Ed Rooney]

I thought I heard Rolex tests to 120% of depth rating.

I think the crystal and possibly the caseback of the GMTIIc are thinner than the Sub. All triplock crowns are good to extreme depths, far exceeding the DS.

[BigHat]

Originally Posted by Ed Rooney

I thought I heard Rolex tests to 120% of depth rating.

I think the crystal and possibly the caseback of the GMTIIc are thinner than the Sub. All triplock crowns are good to extreme depths, far exceeding the DS.

The Sub and GMT-IIC share the same crystal. The part number is the same. Vanessa confirmed it.

[acce1999]

The crystal is the same on all 36 mm Datejusts and sports models (2 mm) with the exception of the SD (3 mm).

The difference is the thickness of the caseback. Vanessa recently posted some measurements, and promised to get back as soon as she has more info. She also informed us that there is a different crystal gasket on the sports models, but I do not know if it is the same for all models.

Example: 16610 1.51 mm, 16750 0.72 mm.

The triplock is supposedly good to 500 atm, so that is not an issue, it is about bending of the caseback at high pressure.

I would guess that any Oyster model would do fine at 200 meters or even 300 meters. I am more concerned about the person bringing it down there. Let me know when the GMTII-c passes 100 meters... I have only been down to 16 meters myself...

Here is what Rolex themselves once said in an ad, and if we assume the ad is based on the truth (and applicable on the non-plexi models), and that the sapphire crystal itself is good to at least 300 meters we can conclude that the Oyster case is capable of MUCH more than 100 meters ("at 1900 feet the back showed signs of bending"):



Best,

A

[BigHat]

You beat me to it.

Here's the thread on the subject.

http://www.rolexforums.com/showthrea...hlight=vanessa

Salient Point:

Originally Posted by Vanessa
The crystal is NOT thinner on a GMT compared to a Submariner. They are exactly the same!
The only crystal that is thicker is on the Seadweller.
All the crystals on the oyster cases have the same thickness for that matter... the datejust, airking, day-date, explorer,... all have the same crystal! The only difference with these compared the the ones with rotating bezels (TOG excluded), is the height of the gasket

[acce1999]

In addition: I read that someone tested his YM to 300 meters without problems. Also, there is a professional diver that has a site where he says he has taken his GMT IIc to below 100 (real, not pressure chamber) meters (if I remember correctly). Can not remember the site. I'll see if I can find it.

Best,

A

[Z-Sub]

Case back. If you compare the case back of different watches, thicker case backs goes to SD and sub.
But I do also believe the New GMT-IIC has potential to go deeper than the 16710.
But, does that really matter for most of us who don't go below 100M, ever!??

[BigHat]

Originally Posted by Z-Sub

But, does that really matter for most of us who don't go below 100M, ever!??

99.9% of these watches never go deeper than the bottom of a hot tub.

[mfer]

I know, I know. I'll never go below 100m, much less 3m. Just wondering why is all. Makes sense they don't want to make the sub seem obsolete. But if I had to guess, the GMT IIc looks like it could go deeper than the sub with the supercase. Have no clue. Just a guess. I have NO evidence to support that.

[BigHat]

Originally Posted by mfer

I know, I know. I'll never go below 100m, much less 3m. Just wondering why is all. Makes sense they don't want to make the sub seem obsolete. But if I had to guess, the GMT IIc looks like it could go deeper than the sub with the supercase. Have no clue. Just a guess. I have NO evidence to support that.

Well the same crown and crystal for sure. The case itself isn't a weak link. That leaves the case back. GMT-II is thinner, jury's out on the II-C. My GUESS would be the II-C is better than 100m watch, after all, it was that with the double-lock crown in the earlier model. Will it get to 1000'? Don't know, don't care.

[f16570]

Would be interesting if someone actually tested their watch to the specified depth.
I unfortunately can only hold my breath for 31 seconds so that rules me out.

[SPORTSFAN]

I like the Jeremy Clarkson quote on this ......something like.......

My watch is waterproof to 1000 feet, which is completely pointless to me.However it is comforting to know that when I drop it in the sink it will be OK......



Regards Mike.

[subman999]

interesting comments guys,all I need to know is can I shower, swim, and snorkel wearing my Gmt11c, I think so!!...and if you must dive, 100m is deeper than most military clearance divers ever go, and then you wear a dive computer you can not see a watch below 5 meters in most waters around the world.

[BigHat]

Originally Posted by subman999

interesting comments guys,all I need to know is can I shower, swim, and snorkel wearing my Gmt11c, I think so!!...and if you must dive, 100m is deeper than most military clearance divers ever go, and then you wear a dive computer you can not see a watch below 5 meters in most waters around the world.

If you find this discussion on the GMT-IIC silly think about the SDDS. If you need a macho fix buy a MTM Black Seal, it's the ONLY waterproof watch validated to 29,000 feet. Oh, and you get a great looking, accurate,tritium tubed watch with no glare thanks to the oil filled case. Those are the attributes that got me excited about it-- and you save $7K over the SDDS. Oops, not a Rolex -- nevermind.