Trimix Diver (helium-based gas mixes)

A Trimix Diver uses a gas blend containing helium, nitrogen, and oxygen. This mixture helps prevent nitrogen narcosis at depth.

Technical divers use these mixes for dives deeper than 40 m. While air becomes narcotic quickly, helium stays stable. A common mix for a 60 m dive might contain 18% oxygen and 35% helium. These gases allow better mental clarity during complex decompression tasks. You will often see this in wreck diving or deep reef exploration.

Always check your gas density before a descent. I once saw a diver forget how heavy a high-helium mix feels on the lungs during a long deco stop in 2018. Helium makes your voice high, but it also changes how you breathe. Monitor your gas consumption closely because helium is expensive and burns through tanks fast.