top of page
  • Rahul Vijh

Exploring the Marvel of Helium Release Valves in Dive Watches

Dive watches have been an essential tool for professional and recreational divers for many decades. These timepieces are designed to withstand the rigors of underwater exploration and provide accurate timekeeping in the most challenging conditions. One critical feature that ensures the durability and functionality of dive watches is the helium release valve (HRV). In this article, we will delve into the fascinating world of HRVs, understanding what they are, how they work, and why they are crucial for divers.

What Is a Helium Release Valve?

A Helium Release Valve, often abbreviated as HRV, is a specialized feature found in some high-end dive watches. It is a small, unobtrusive valve designed to release helium gas that may accumulate within the watch during deep-sea diving operations. The presence of helium in a dive watch is a common occurrence during saturation diving or extended periods spent in pressurized environments.

Helium molecules are exceptionally tiny and can permeate the seals and gaskets of a dive watch over time. While this may not be a significant issue during regular recreational diving, it becomes critical during saturation diving, where divers live in a pressurized environment for extended periods and breathe a helium-oxygen mixture. The helium molecules can enter the watch case and increase the internal pressure, potentially leading to damage or malfunction.

How Does It Work?

The helium release valve operates on a simple principle: it allows excess helium gas that has seeped into the watch to be released gradually. It prevents the watch crystal or case from being forcibly expelled when the diver ascends to the surface and the pressure inside and outside the watch begins to equalize.

The HRV is typically located on the side of the watch case, integrated into the design. It has a one-way valve that opens to release the accumulated helium when the internal pressure exceeds a certain threshold. This ensures that the watch remains watertight during the dive but can safely vent helium as needed.

History in Patents

HRVs began to appear in dive watches during the mid-20th century, with several watch manufacturers experimenting with different designs and mechanisms to address the issue of helium accumulation in deep-sea diving. Brands like Rolex and Doxa are often credited with pioneering the development and popularization of HRVs.

Rolex is known for its contribution to dive watch technology with the Rolex Sea-Dweller, introduced in the 1960s. The Sea-Dweller featured an early version of the helium escape valve to release helium gas that could accumulate during saturation diving. Rolex patented its HRV in 1967 (and received the grant in 1970) as CH492246A.

Patent CH492246A, titled “Montre étanche” (1967), assigned to Rolex Montres S. A.

Doxa, a Swiss watchmaker, is also recognized for its SUB concept and the SUB 300 dive watch. Released in 1967, the SUB 300 featured the "US Navy no-deco" concept, including a helium release valve, which helped make it a favorite among professional divers. Interestingly Doxa filed its patent CH489048A, titled “Montre de plongeur”, a few months before Rolex – albeit with a notably take on the HRV. Rolex’s variant of course became (and has remained the more) popular design, fueled in no small amount by having similar overall design as Rolex’s Submariner line of watches.

Patent CH489048A, titled “Montre de plongeur” (1967), assigned to Manuf des Montres DOXA S. A.

Why Are Helium Release Valves Essential for Dive Watches?

Prevents Damage: Without an HRV, the increasing internal pressure from trapped helium gas could lead to catastrophic damage to the watch, including shattered crystals or blown-off case backs. HRVs protect the watch from these potential issues.

Safety for Saturation Divers: Saturation divers often live and work in high-pressure environments for extended periods. Having a reliable HRV in their dive watch is essential for safety and ensuring the proper functioning of their timepiece.

Durability: Dive watches are designed to withstand the harshest underwater conditions, and HRVs contribute to their overall durability and longevity. The presence of an HRV adds another layer of robustness to these timepieces.

Maintaining Accuracy: Maintaining the integrity of the watch case and crystal ensures that the watch's accuracy is preserved, even in challenging conditions.

Versatility: While HRVs are primarily associated with professional dive watches, they can also be found in some recreational dive watches. This versatility ensures that all divers, regardless of their experience level, can benefit from this technology.


Helium release valves are a testament to the precision and engineering that go into designing high-quality dive watches. They play a vital role in maintaining the structural integrity and accuracy of these timepieces, especially in extreme diving conditions. Whether you're a professional saturation diver or an enthusiastic recreational diver, a dive watch equipped with an HRV is an invaluable tool that enhances safety and reliability during your underwater adventures. So, the next time you strap on your dive watch and explore the depths of the ocean, take a moment to appreciate the marvel of the helium release valve keeping your watch ticking with precision.



Recent Insights
bottom of page