Why diving watches need a helium valve

February 9, 2022By Bonetto Cinturini

The wristwatch is a dear companion of adventures to take with you not only to be able to check the time, but also to enhance and characterize your own style. In recent decades, watches have evolved from a technological standpoint, providing extraordinary performance in terms of precision but also in terms of water resistance, resistance to the action of climate agents and robustness.

This allows you to wear the watch to the sea, in the mountains and on any other occasion, including diving. In this regard there are some diving watches on the market that feature the helium valve. Perhaps the most careful customers will have noticed this although in many models the valve is not inserted.
But what’s the helium valve for? Why would it be useful in diving?
Let’s find out together!

What a helium valve is and how it works

To ensure greater safety and to protect a diving watch from strong pressures and other risky situations, many brands have decided to mount a helium valve. It is a device that plays a safety role by allowing the escape of helium molecules during dives both in the saturation phase and in the decompression phase. 

This is an important aspect to consider especially for people who love diving at deep depths, subjecting their body and watch to a pressure of no little account. In the depths of the sea divers find themselves in an actual hyperbaric chamber and must breathe using a mixture of gas known in jargon as Heliox. It is basically a mixture of helium and oxygen. 

As a matter of common knowledge, in the air you breathe every day there is a mix of gases, especially oxygen and nitrogen. The latter is in fact replaced in the hyperbaric chamber by helium. It is a functional choice that ensures important performance, but at the same time could pose a risk to people’s health and to the use of some devices such as the diving watch. Actually, if a situation of condition pressure were to be foreshadowed, for the human body there would be the risk of narcosis and therefore loss of consciousness. 

Moreover, due to their very small size, helium molecules can infiltrate the case of any diving watch regardless of the materials used and of their technology. In particular, they exploit the small gaskets that allow the watch to be used under water. Once the helium molecules are inside the watch case, it may happen that in the decompression phase they cannot get out quickly so there would be a dangerous effect that eventually leads to the crystal glass getting shattered. 

Sure enough, this is a major damage to the watch. Because of this problem, all the most important brands in the industry have decided to mount the helium valve on their underwater models, although it is good to know that in amateur diving, a few meters deep, there is no risk of breakage for the crystal glass even in the absence of a valve.

The first helium valve in history

The need to find technologically advanced solutions to manage the possible access of helium molecules in the watch case became apparent as the most important professional divers began to complain about a common problem: the shattering of the crystal glass. A situation that used to occur ever more frequently because of the new diving equipment that allowed athletes to reach points much deeper and to break record upon record. This situation was evident not only in competitions, but also during training with damages of no small importance. 

The shattering would occur during the decompression phase, so the best companies charged their technicians to study in detail the phenomenon so as to understand the causes and find solutions. In the early 1960s, Rolex began a fruitful collaboration with Comex, a French company specializing in diving equipment. Thanks to this collaboration, the helium valve was devised and built. 

Initially, to remedy the problem in the shortest possible time, Rolex decided to supply Comex with Submariner watches modified to create a highly coveted product, the Rolex Comex series. Today they are very appealing to enthusiasts and especially collectors because they are extremely rare and extremely valuable. 

A few years later, more precisely in 1967, Rolex further improved its models with a valve integrated on the left side, as in the case of the Sea-Dweller. It immediately got an incredible response because the advertising campaign of the company based in Geneva was not so much focused on the decision to remove the magnifying glass on the date window, but rather on the impermeability guaranteed up to a depth of 610 meters below the sea level. These early models of professional divers’ watches as well are now unavailable and particularly expensive.

The new version of the Rolex Sea-Dweller

On the 50th anniversary of the launch of the first historic Sea-Dweller model, Rolex wanted to launch a new version that has some technological, but also shape-related and dimensional differences. In fact, this new version has been slightly enlarged starting from the initial 40 mm and reaching the current 43 mm. The case is waterproof up to 1220 meters corresponding to a pressure of 120 bar and there was the insertion of the Cyclops lens on the calendar. 

A little peculiarity about the reintroduction of the magnifying glass for the calendar. In fact, it seems that the Swiss brand has decided to start using this old solution again because of the points of view that have been shown on several occasions by the Rolex customers and fans. Technological improvements have also been introduced, such as the 3235 manufactured caliber with the Chronergy escapement, which guarantees a power reserve of almost 70 hours. Like in so many other models from this famous and appreciated manufacturer around the world, the main feature is precision. It can be ascertained based on the certification that the daily inaccuracy can oscillate between -2 and +2 seconds.

Other diving watches equipped with a helium escape valve

There are many other divers’ watches that feature the helium escape valve, therefore allowing professionals to dive safely without risking shattering the crystal. 

The Seamaster Planet Ocean 600 M is a professional model made by Omega that has three hands with date displayed at the 3 o’clock position. The diameter is of 43.5 mm, and it is waterproof up to 600 meters deep which is comparable to a pressure of 60 bar.
Like Rolex, this company has also decided to insert the helium escape valve on the left side but there is a difference in use because in order to make use of the valve, the Omega watch requires a manual rotation, while for the Sea-Dweller this occurs automatically. 

Tudor Pelagos is a chronometer made of titanium and equipped with a helium escape valve. It operates automatically and it is also integrated in the case on the left side at the 9 o’clock position. As already mentioned, the case is made of titanium, which guarantees the watch’s robustness while keeping it lighter than steel. The diameter is slightly smaller with its 42 mm and there is a highly scratch-resistant rotating bezel covered in ceramic. This watch allows you to dive safely up to 500 meters deep, so under a pressure of 500 bar. 

A very interesting titanium bracelet with a buckle safety clasp has been implemented with a mechanism that adjusts itself adapting to the environmental pressure. Basically, when the pressure increases by going deeper, the bracelet shrinks allowing greater resistance. As a result, when ascending, the bracelet senses the lower pressure and then loosens. It may look like a function for the sake of itself, but in reality, it is particularly useful because it adapts to the diving suit allowing maximum grip. Finally, it should be noted that, like Rolex, this product also provides a power reserve of 70 hours.