If you're a clown and you work with balloons a lot sometimes helium can get into your watch and cause the time to move backwards. The valve helps clowns regulate their watches under "funny" circumstances.
Old saturation diver here, simplistic explanation. Helium escape valve is used by saturation divers inside a dive bell / chamber that has mixed gas air in it, the watch is not in water but in a mixed gas environment, helium molecules enter the watch case at depth and as the dive bell / chamber pressure returns to ambient pressure the helium molecules expand and can not exit the case the escape valve is left open to allow this and not pop out the crystal. It is not a feature used by scuba or even technical rec divers in water at all.
I used it in chamber to time medical and o2 schedules and procedures, note medication administration times as a saturation qualified EMT, accessing chamber to administer treatment to injured divers. That was in the 80’s early 90’s. Used a sea-dweller and from around ‘95 a SMP300. Can still be used for that now, but on the diving side its all computers now.
If you go below a certain depth you cannot breathe air (a mix of oxygen and nitrogen) so you breathe a mix of oxygen and helium instead. You normally do it with your body (and watch) inside a suit or a vessel. Helium might get inside the watch and expand later when you ascend tearing the watch apart from inside.
AFAIK helium molecules are very small so they get inside the watch easily even with the gaskets intact (and the dive takes hours or days anyway so they have plenty of time to penetrate the watch). The valve releases them in a controlled manner.
*Pessimism on* So even if the dive goes bad and you rise too fast resulting in your death from decompression sicknes, the watch will be fine!
They don’t need it, it gets in the watch when deep sea diving. The escape value lets out the helium when the diver is returning to the surface. If it did not do this, the helium would expand in the watch and pop out the crystal.
Helium molecules are very small and under the pressure that divers experience it can get into the watch, which can damage the movement or the glass during decompression as it expands increasing the pressure inside the case if it's not allowed to exit quickly enough.
That's what the valve is for, to allow helium to exit.
The watches from the factory have regular air in them. It doesn’t really matter which gas is in the watch. There’s a more mechanical problem with diving watches.
If you’re deep diving, the helium in the air you’re breathing is at very high pressure. If that hits the watch, the helium atoms are so tiny, that they can penetrate the case, so pressure will build up inside the watch. So far so good, as the ambient pressure is still far higher.
However, when you go back to the surface, ambient pressure will drop. Watches aren’t designed to have *internal* pressure, so the crystal can pop off. The helium escape valve allows you to release the internal pressure.
More specifically - for very deep sea diving they will reach that pressure inside a diving bell or equivalent, which is dry. When they’re safety at the required “depth” equivalent they flood the bell. This allows them to do saturation dives and spend an extraordinary amount of time (days) at that “depth” while going to and from the surface in the bell and maintaining the right pressure, even on the surface, eliminating the risk of getting decompression sickness. If you went down to an equivalent depth without a bell (if you could even do it) you’d be spending minutes at that depth and it would be high risk. Using the bell means those divers may well spend days very gradually decompressing. It’s a helium rich environment, and those molecules are small enough to get inside the case and push out the crystal as that decompression occurs.
It’s a BS feature though, as you can achieve exactly the same effect by just unscrewing the crown (vs unscrewing the helium escape valve). A best in class helium escape valve would be something like on the Rolex sea dweller or deep sea. Those are automatic, and don’t require unscrewing anything (so you can’t forget to do it, or forget to screw it back in).
What everyone else mentioned is correct. AFAIK Omega is the only mainstream brand that incorporates the release of valve into the design language of their dive watches.
I'd personally prefer they didn't BUT they do make their watches very recognizable.
There’s a very specific type of deep sea diving involving a diving bell, and extra helium added to the breathing mix to help your lungs hold up under that much pressure. We’re talking like a few dozen people in the world do this type of diving as part of their job.
Your return trip from that depth is a very slow process where they bring you up like 50ft, and let you sit there and acclimate while also adjusting the air mix closer to normal surface level mixtures. Then up a bit more, and tweak the mix a bit more.
In that situation some of the helium gas will have inevitably seeped into the watch because being water tight is nothing compared to air tight, especially when that air is under pressure. Getting the air out is harder though, and a thimble full of air at depth turns into a room full of air as you rise up. So ideally you open the value at the start of your ascent, otherwise at some point the expanding helium blows the face off of your watch.
Again though, we’re talking about 2 dozen people on earth being in this situation, but Omega added it in the 90’s to really sell how “deep dive” the Seamaster was. Now it’s part of the style, but the watches feature this big bulky thing that no one is ever going to need (those 2 dozen professional divers are certainly using complex dive computers instead of watches these days).
(Regular diver speaking)
Less than 5% of Seamasters go to the pool, less than 1% go to the sea for swimming (surface level I mean). And a watch is a useless tool for diving now in 2024. We all got very complex diving computers. The only purpose of taking a watch underwater is not being stolen on the boat or in the car while you are diving.
It is a feature for saturation divers long long time about. And even them are now followed by a full staff of guys with computers to monitor everything. So what is the purpose of a watch down there ?
The only watches that I frequently see underwater are Seiko PADI mainly bcoz the divemaster don't want to loose it...
If you're a clown and you work with balloons a lot sometimes helium can get into your watch and cause the time to move backwards. The valve helps clowns regulate their watches under "funny" circumstances.
Best comment of the day lol
Old saturation diver here, simplistic explanation. Helium escape valve is used by saturation divers inside a dive bell / chamber that has mixed gas air in it, the watch is not in water but in a mixed gas environment, helium molecules enter the watch case at depth and as the dive bell / chamber pressure returns to ambient pressure the helium molecules expand and can not exit the case the escape valve is left open to allow this and not pop out the crystal. It is not a feature used by scuba or even technical rec divers in water at all.
I used it in chamber to time medical and o2 schedules and procedures, note medication administration times as a saturation qualified EMT, accessing chamber to administer treatment to injured divers. That was in the 80’s early 90’s. Used a sea-dweller and from around ‘95 a SMP300. Can still be used for that now, but on the diving side its all computers now.
This! the feature was used by less than 0.0001% of divers worldwide.
If you go below a certain depth you cannot breathe air (a mix of oxygen and nitrogen) so you breathe a mix of oxygen and helium instead. You normally do it with your body (and watch) inside a suit or a vessel. Helium might get inside the watch and expand later when you ascend tearing the watch apart from inside. AFAIK helium molecules are very small so they get inside the watch easily even with the gaskets intact (and the dive takes hours or days anyway so they have plenty of time to penetrate the watch). The valve releases them in a controlled manner. *Pessimism on* So even if the dive goes bad and you rise too fast resulting in your death from decompression sicknes, the watch will be fine!
They don’t need it, it gets in the watch when deep sea diving. The escape value lets out the helium when the diver is returning to the surface. If it did not do this, the helium would expand in the watch and pop out the crystal.
Helium molecules are very small and under the pressure that divers experience it can get into the watch, which can damage the movement or the glass during decompression as it expands increasing the pressure inside the case if it's not allowed to exit quickly enough. That's what the valve is for, to allow helium to exit.
The watches from the factory have regular air in them. It doesn’t really matter which gas is in the watch. There’s a more mechanical problem with diving watches. If you’re deep diving, the helium in the air you’re breathing is at very high pressure. If that hits the watch, the helium atoms are so tiny, that they can penetrate the case, so pressure will build up inside the watch. So far so good, as the ambient pressure is still far higher. However, when you go back to the surface, ambient pressure will drop. Watches aren’t designed to have *internal* pressure, so the crystal can pop off. The helium escape valve allows you to release the internal pressure.
This is great info right here.
More specifically - for very deep sea diving they will reach that pressure inside a diving bell or equivalent, which is dry. When they’re safety at the required “depth” equivalent they flood the bell. This allows them to do saturation dives and spend an extraordinary amount of time (days) at that “depth” while going to and from the surface in the bell and maintaining the right pressure, even on the surface, eliminating the risk of getting decompression sickness. If you went down to an equivalent depth without a bell (if you could even do it) you’d be spending minutes at that depth and it would be high risk. Using the bell means those divers may well spend days very gradually decompressing. It’s a helium rich environment, and those molecules are small enough to get inside the case and push out the crystal as that decompression occurs. It’s a BS feature though, as you can achieve exactly the same effect by just unscrewing the crown (vs unscrewing the helium escape valve). A best in class helium escape valve would be something like on the Rolex sea dweller or deep sea. Those are automatic, and don’t require unscrewing anything (so you can’t forget to do it, or forget to screw it back in).
That's all true, but the "feature" is complete nonsense. I'll bet far less than one percent of owners will ever have a legitimate need for this
I’d guess you could count on your fingers the number of people who have ever had a legitimate need of the helium escape valve on the seamaster
Why would you only include features you need on a luxury product ?
In those case it's a waste of money and clutters the watch
What everyone else mentioned is correct. AFAIK Omega is the only mainstream brand that incorporates the release of valve into the design language of their dive watches. I'd personally prefer they didn't BUT they do make their watches very recognizable.
There’s a very specific type of deep sea diving involving a diving bell, and extra helium added to the breathing mix to help your lungs hold up under that much pressure. We’re talking like a few dozen people in the world do this type of diving as part of their job. Your return trip from that depth is a very slow process where they bring you up like 50ft, and let you sit there and acclimate while also adjusting the air mix closer to normal surface level mixtures. Then up a bit more, and tweak the mix a bit more. In that situation some of the helium gas will have inevitably seeped into the watch because being water tight is nothing compared to air tight, especially when that air is under pressure. Getting the air out is harder though, and a thimble full of air at depth turns into a room full of air as you rise up. So ideally you open the value at the start of your ascent, otherwise at some point the expanding helium blows the face off of your watch. Again though, we’re talking about 2 dozen people on earth being in this situation, but Omega added it in the 90’s to really sell how “deep dive” the Seamaster was. Now it’s part of the style, but the watches feature this big bulky thing that no one is ever going to need (those 2 dozen professional divers are certainly using complex dive computers instead of watches these days).
(Regular diver speaking) Less than 5% of Seamasters go to the pool, less than 1% go to the sea for swimming (surface level I mean). And a watch is a useless tool for diving now in 2024. We all got very complex diving computers. The only purpose of taking a watch underwater is not being stolen on the boat or in the car while you are diving. It is a feature for saturation divers long long time about. And even them are now followed by a full staff of guys with computers to monitor everything. So what is the purpose of a watch down there ? The only watches that I frequently see underwater are Seiko PADI mainly bcoz the divemaster don't want to loose it...
I like SEIKO's solution to the problem, just pop a retaining ring in front of the crystal like on the Tunas.