Trimix (breathing Gas) - History As A Diving Gas

History As A Diving Gas

1919

Professor Elihu Thompson speculates that helium could be used instead of nitrogen to reduce the breathing resistance at great depth. The effects from narcosis was not proven until the salvage of the USS Squalus in 1939. Heliox was used with air tables resulting in a high incidence of decompression sickness so the use of helium was discontinued.

1925

The US Navy begins examining helium's potential usage and by the mid 1920's lab animals were exposed to experimental chamber dives using heliox. Soon, human subjects breathing heliox 20/80 (20% oxygen, 80% helium) had been successfully decompressed from deep dives.

1937

Several test dives are conducted with helium mixtures, including salvage diver Max "Gene" Nohl's dive to 127 meters.

1939

US Navy used heliox in USS Squalus salvage operation.

1965

First saturation dives using heliox.

1970

Hal Watts performs dual body recovery at Mystery Sink (126 m). Cave divers Sheck Exley and Jochen Hasenmayer use heliox to a depth of 212 meters.

1979

A research team headed by Peter B. Bennett at the Duke University Medical Center Hyperbaric Laboratory began the "Atlantis Dive Series" which proved the mechanisms behind the use of trimix to prevent High Pressure Nervous Syndrome symptoms.

1987

First mass use of trimix and heliox: Wakulla Springs Project. Exley teaches non-commercial divers in relation to trimix usage in cave diving.

1991

Billy Deans commences teaching of trimix diving for recreational diving. Tom Mount develops first trimix training standards (IANTD). Use of trimix spreads rapidly to North East American wreck diving community.

1994

Combined UK/USA team, including leading wreck divers John Chatterton and Gary Gentile, successfully complete a series of wreck dives on the RMS Lusitania expedition to a depth of 100 meters using trimix.

1995

The National Oceanographic and Atmospheric Administration (NOAA) and Key West Divers team up to conduct the first NOAA-sponsored trimix dives on the wreck of USS Monitor off Cape Hatteras, NC. NOAA's mix, initially called "Monitor Mix" became NOAA Trimix I, with decompression tables published in the NOAA Diving Manual.

2001

The Guinness Book of records recognises John Bennett as the first scuba diver to dive to 1000 ft, using Trimix.

2005

David Shaw sets depth record for using a trimix rebreather, dying while repeating the dive.

Source: "Trimix and heliox diving". February 14, 2002. http://www.techdiver.ws/trimix_eng.shtml. Retrieved 2008-10-07.