What Is the Helium Escape Valve?

The helium escape valve is a feature found on professional-grade Omega Seamaster dive watches, such as the Seamaster Diver 300M and Planet Ocean models. It's designed specifically for saturation diving, where divers live in pressurized environments and breathe gas mixtures containing helium.

In those conditions, tiny helium molecules can seep into a watch case. Upon surfacing, if the internal pressure isn’t released, it can cause the crystal to pop off. The helium escape valve lets the gas safely exit the watch, preventing damage during decompression.

Types of Helium Escape Valves

Omega uses two types of HEV systems:

1. Manual Helium Escape Valve – Requires user operation.

2. Automatic Helium Escape Valve – Functions automatically during decompression.

This guide focuses on the manual valve, commonly found on the Seamaster Diver 300M.

How to Use the Manual Helium Escape Valve

1. Before Diving

• Do not open the valve. Ensure the helium escape valve is screwed in tightly. The watch is fully water-resistant in this state.

• The valve is typically located at the 10 o'clock position on the case.

2. During the Dive

• The valve remains closed at all times during diving.

• Water will not enter the watch as long as the crown and valve are secured properly.

3. During Saturation Diving (Decompression Phase)

• When the diver is decompressing in a pressure chamber after a long saturation dive, the internal pressure in the watch might increase due to helium buildup.

• To safely release the pressure, unscrew the valve counterclockwise 1–2 turns (do not remove it).

• The helium will escape slowly. You may not hear anything or see bubbles—this is normal.

4. After Decompression

• Once back at normal atmospheric pressure, re-tighten the valve clockwise.

• Make sure it is securely screwed in to maintain full water resistance.

When NOT to Use It

• Do not open the valve underwater.

• Do not use it for recreational diving or swimming—it’s unnecessary.

• Avoid unscrewing it unless you’ve been in a pressurized helium environment.

Important Notes

• If the valve is left unscrewed, the watch is not water-resistant and may allow water to enter.

• The valve is only needed in commercial or saturation diving conditions.

• Omega watches with automatic HEVs (like some Planet Ocean models) do not require manual action—the valve activates on its own when pressure builds.

Summary

To use Omega’s helium escape valve:

• Keep it closed during normal use and diving.

• Only open it during decompression after saturation diving.

• Never use it underwater or for casual diving.