How nitrox came to recreational diving.

This page tells the history of a debate. The arguments quoted from 1992 are recorded as they were published then, not as current guidance. What nitrox equipment involves today is on nitrox equipment, and nitrox training is listed on specialty certifications.

Navy and NOAA origins

A July 1992 article in Dive Training by Alex Brylske traces enriched air back to Christian Lambertsen, who it says proposed it in 1943 as a way to reduce decompression obligations. The same article says enriched air was standardised for military scuba, with procedures in the US Navy Diving Manual, in 1959, and that the Navy used it in its Mark V system from 1962. Those dates could not be checked against Navy sources. Wikipedia says more generally that the US Navy documented military enriched-air procedures in the 1950s. Lambertsen's own story is on Lambertsen and the word SCUBA.

At NOAA, the central figure in the sources is Dr J. Morgan Wells. NAUI's memorial page for Wells says he developed the Equivalent Air Depth formula in 1970, was appointed director of the NOAA Diving Program in 1978, and that the NOAA Nitrox I standards were developed that year from his work, followed by NOAA Nitrox II in 1990. X-Ray Magazine (Simon Pridmore, 4 November 2023) gives a slightly different sequence: Wells proposed nitrox at NOAA in 1977, NOAA approved NOAA Nitrox I across the agency in 1978, and its tables appeared in the NOAA Diving Manual in 1979.

When Wells's nitrox work began is therefore dated two ways. Wikipedia dates his start on enriched-air procedures to 1970, the year NAUI gives for his formula; X-Ray Magazine dates his nitrox proposal to 1977. A search summary of the X-Ray article reports Wells explaining that he deliberately left the mix out of the name "NOAA Nitrox I" so that divers would not be tempted to experiment with it. Wells died on 28 July 2017, aged 77; NAUI had inducted him into its Hall of Honor in 2016, alongside Dick Rutkowski.

The first sport courses, 1985 to 1992

X-Ray Magazine says Dick Rutkowski directed NOAA's Diving/Hyperbaric Training and Diver Treatment Facility from 1973 to 1985, then retired and founded Hyperbarics International. Wikipedia says he formed the International Association of Nitrox Divers (IAND) in 1985 to teach nitrox to recreational divers. Undercurrent (September 2016) says Rutkowski ran the first recreational nitrox certification course, from his base in Key Largo, and calls it the first of its kind.

X-Ray Magazine says a 1988 workshop held by NOAA and Harbor Branch proposed the name "Enriched Air Nitrox", or EAN, and that Rutkowski and Ed Betts formed a second organisation, American Nitrox Divers Inc (ANDI), the same year. IAND later passed to Tom Mount, on dates the sources give differently: X-Ray Magazine says Rutkowski sold IAND to Mount in 1990 and that Mount was its chief executive from 1992 to 2005, while Wikipedia says Mount joined in 1991 and became president in 1992. IAND became the International Association of Nitrox and Technical Divers (IANTD) in 1992 by most accounts, or 1991 by one.

The 1992 Dive Training article said recreational divers had made tens of thousands of enriched-air dives between 1985 and 1991, and that by mid-1992 ANDI and IAND had certified nearly 300 instructors and more than 4,000 divers. Those are the figures as published in 1992.

"Devil gas": the controversy

Undercurrent says Bill Gleeson, editor of Skin Diver Magazine, called nitrox "devil gas" and said in print that he would never use it; other sources spell his name Gleason. The dispute then reached the DEMA trade show.

• Michael Menduno, writing for Divernet (26 July 2019), says that in the autumn of 1991 DEMA's founder and executive director, Bob Gray, moved to bar nitrox vendors and training agencies such as IAND and ANDI from the DEMA trade show. Menduno says the move was reportedly prompted by the Cayman Water Sports Association and was supported by Skin Diver magazine.
• Undercurrent says DEMA rejected an IANTD booth application in 1991, citing safety concerns about nitrox.
• Menduno says an Enriched Air Nitrox Workshop was held in Houston in January 1992, days before that year's DEMA show, after which Gray rescinded the ban. The workshop's findings were published in technicalDiver, volume 3.1, in July 1992.

Skin Diver's own campaign against nitrox is described two ways. Menduno says it ran a three-part series in the last three months of 1992. Dive Training's publisher's note says Skin Diver ran four editorials by different experts in a single issue, all opposed to nitrox.

The arguments as they stood in 1992

Brylske's 1992 article summed up both sides. Supporters pointed to longer no-decompression limits, or to using enriched air as an added safety margin. Opponents pointed to oxygen toxicity at shallower depths, the hazards of handling oxygen, cylinders filled with the wrong mix, and the cost, availability and training it would demand. The same article quoted PADI's vice-president for training, Drew Richardson, as saying PADI did not yet sanction any mixture other than air and that its liability insurance did not cover enriched-air instruction. It said NASDS favoured air tables only.

The agencies come round

NAUI says it adopted the NOAA nitrox standards in 1992 and was the first recreational agency to do so; that is NAUI's claim. The 1992 Dive Training article says that NAUI by then allowed enriched-air diving through approved programmes and that its liability policy covered enriched-air instructors.

When PADI followed is disputed. Wikipedia says PADI announced full educational support for nitrox in 1996. Menduno says that by 1995 PADI, BSAC, NASE and SSA were already offering nitrox training. PADI's own announcement was not found during research. BSAC's milestones page says BSAC approved nitrox for its members in 1995.

PADI's blog today calls its Enriched Air Diver course its most popular specialty, which is PADI's claim. The same years produced the term "technical diving" and the first technical diving conference, told on cave and technical diving.