[FlyPenFly]

Omega Seamaster Pro Chronograph
Omega Apnea
Omega Planet Ocean Chronograph
Ball Hydrocarbon Trieste
Ball EMII Diver Chrono
IWC Aquatimer Chronograph (not sure about the newest 2000 models)
JLC Master Compressor Diving Chronograph
UTS 600M Pro Diver Chrono
Sinn U1000
Breitling Avenger Seawolf Chronograph
Breitling Chrono Avenger M
Ebel 1911 Discovery Chronograph
Tag Heuer Aquagraph
Blancpain Fifty Fathoms Chronograph

And I've just been told by EBEL Service that the Discovery 1911 Chronograph can also be used underwater because of a double gasket feature.

Surprisingly, the Doxa chronos cannot be operated underwater.

Anyone else have a watch to add?

 

[Gabyeah]

Here is a thread with a list to help! Cheers!

https://www.watchuseek.com/showthread.php?p=1895283

 

[Paperclip]

Blancpain Fifty Fathoms Chrono

Manufacturer's claim:
Blancpain innovates by interpreting the Fifty Fathoms in a chronograph version. This choice will delight professional divers, as well as all nautical and water sports enthusiasts. It called for some impressive feats in terms of its construction, particularly with regard to the pushers. Most chronographs cannot be handled while diving, but thanks to a system of special joints concealed within the case, Blancpain has succeeded in making the push-buttons perfectly water-resistant and operational at depths of 300 metres. The Fifty Fathoms Chronograph can thus truly be used in oceans or lakes, and not only above water level.

 

[FlyPenFly]

Here is a thread with a list to help! Cheers!

https://www.watchuseek.com/showthread.php?p=1895283

Thanks, added.

I am curious by what Lysander posted in that thread:

Any water resistant chronograph will be operational under water (and remain water resistant.) The depth that operating the pusher will force water into the case will, however, be somewhat less than the full depth.

This is, of course, dependent on the conditions of the gaskets.

I would think the motion of the pusher would risk water leaking in.

 

[lysanderxiii]

Thanks, added.

I am curious by what Lysander posted in that thread:

Any water resistant chronograph will be operational under water (and remain water resistant.) The depth that operating the pusher will force water into the case will, however, be somewhat less than the full depth.

This is, of course, dependent on the conditions of the gaskets.

I would think the motion of the pusher would risk water leaking in.

It also depends on the design of the pusher and where the gaskets are relative to the area(s) of trapped water (if any).

Yes, it increases the risk, but even with increases risk, it does not automatically follow that the leak will occur.

 

[FlyPenFly]

I'm a little confused by what Ebel Service has told me on their 1911 Disco Chrono

"Dear Customer,
I confirm you that you can use the pushers underwater. This watch is made for this; there are 2 gaskets by pusher.
With our kind regards,"

Why don't they advertise this?

 

[toxicavenger]

Marcello C

 

[rsr911]

Anonimo Professionale Chronograph will work under water.
One of my Grail watches!!!

 

[discordianist]

Also I've been told that Prometheus Ocean Diver Chrono can be operated under water, I'll let you know for sure after I've dived with one But that's what they say (and it's pushers are not screw in design but a paddle design so they should also be easy to use with gloves on).

 

[siddhartha]

Doxa TGraph 2007 models (Doxa has stated chrono pushers useable to 200M)

 

[Nalu]

Both threads are missing the 'original' auto dive chronograph, the Seamaster 120C:

 

[lysanderxiii]

I'm a little confused by what Ebel Service has told me on their 1911 Disco Chrono

"Dear Customer,
I confirm you that you can use the pushers underwater. This watch is made for this; there are 2 gaskets by pusher.
With our kind regards,"

Why don't they advertise this?

Because the rest of the world is not made up of WISes that think to much about watches.

I'll bet 99% of the population totally immerse 3 atm rated watches in water when doing the dishes and jump in the pool with them too....

As to pushers, below is a drawing of a standard Swiss chronograph pusher, with double gaskets. Ordinarily, a double gasket design like this should withstand quite a bit of pressure before anything leaks passed the gaskets. This is double o-ring design is almost identical to the seal arrangement used in hydraulic rams, some of which operate dynamically at 3000 psi (205 atm).

The reason I stated the actual pressure you can operate the pusher without leaking is slightly lower is because water will be trapped in the area marked "A", operating the pusher will increase the pressure in this area, and since it is an incompressible fluid (water), the pressure increase will be significant (unlike the moving under water pressure increase.) However, it should be noted that if the pusher is rated at 30 atm, and the case rated at 20 atm, you should be able to operate the pusher at full test pressure.

The second pusher design, does not allow water to collect in area "A", and therefore, does not have the pumping action problem.

The third one is the typical screw down design, which you can see, seals the same way as the first.

Design #1

Design #2

Design #3

 

[FlyPenFly]

Sweet diagrams. I'm going to guess the Ebel from the way the pusher looks is either the second or third. They look very similar in the pusher area to the Omega Seamaster chronos.

 

[Paperclip]

Lysander, what if the o-rings are sealing the space between the case and the inner crown wall, and not between the case and the crown stem like in your 1st and 3rd diagrams? Is there a sealing system like that?

Here's a rough drawing:

Don't laugh or I'll cry.

 

[FlyPenFly]

Paperclip, I think your design might lead to a wobbily pusher which would compromise the water resistance since it doesn't ensure a consistent seal between the gaskets.

Also, AHAHAHAHAA.

 

[lysanderxiii]

Yes, you could reverse the position of the gaskets on design #1 and have them on the outside of the central column and seal against the inside of the pusher. (shown below, design #4) But, the problem is that area is usually knurled so the pusher cap cannot rotate. Why shouldn't the pusher cap rotate? Because the bottom part is screwed in to the top part and if allowed to rotate, they might come unscrewed. (You may have seen cases where in spite of the anti-rotation knurling, they have become unscrewed anyway.)

Now days, do to cost reasons most less expensive pusher are held in place by a "C" or "E" clip. (shown below, design #5)

Design #4

Design #5

EDIT: I really don't know of any pushers made like design #2 of my first post. The pushers used in the PO are of the conventional design (design #1, original post), they just have a fixed collar on the bottom.

Designs #1, #3 and #5 are the only types I have ever seen used. Seiko has a funny non-permanent design used on the 6139 and 6138 chronographs, but it is a variation of design #5, it just uses the case ring to hold in the pusher, instead of a "C" clip.

 

[sweets]

Hi

What an interesting list.

Not a regular contributor here, but I was linked here from another forum and I see some familiar names.

I wanted to add (speculatively) that the Tutima military line is also similarly able to be operated under water. I have read this several times but cannot now find any written confirmation of this fact. Sorry.

It would stand to reason, as the pushers have no caps to create the pumping action, the pusher stem sits on the inside of the large hinged flat pusher, which is in no way sealed, and would allow water to ingress and egress relatively easily as the pusher moved (and so created no additional pusher).

Whilst writing, I might add that I had an Aquagraph, and on my example, one of the pusher cover plates seemed proud, so took it to my watch guy rather than risk a soaking. He replaced it with new but was appalled at the design, he had no confidence in its abilities at all.

I've not read of any problems with AGs - how do they overcome this problem, anyone know?

Also, how about the Benthos watches? Underwater capable??

Dave

 

[discordianist]

Also I've been told that Prometheus Ocean Diver Chrono can be operated under water, I'll let you know for sure after I've dived with one But that's what they say (and it's pushers are not screw in design but a paddle design so they should also be easy to use with gloves on).

I can now confirm that Ocean Diver Chrono has indeed underwater operatable chrono function. Both by spec and by empiric study of two dives with testing. Neither of the dives were too deep thou (27meters and 31meters). By spec chrono should be usable down to 300 meters and the watch gives no reason to doubt this.

 

[UltraMagnetic]

Patek's 5980 |>

 

[shorinjikempo]

Doxa (2005 edition) 600t-graph can't be used underwater as well as Doxa 200t graph vintage model. Doxa 600t-graph (2007 edition) can be used underwater and it is stated on Doxa collections description.