The scores of PADI-certified nitrox divers around the world have one man to thank for their extended bottom time: Dick Rutkowski. This government scientist brought nitrox gas to the recreational dive community in the 1980s with the first-ever nitrox rec certification, causing a wave of controversy.

But, as he told Scuba Diving in 2004, “science always wins over bullshit,” and the certification has been one of PADI's most popular specialty courses for the last two decades.

This pioneer spent decades advancing the science of scuba gas to make the sport safer, leading hyperbaric chambers and training doctors to handle dive emergencies — in between running radios at the north and south pole, drafting diving safety manuals, and launching multiple companies. He sat down with Scuba Diving days after his 90th birthday to discuss his round-the-world career, dive safety and his career advice for young divers.

Editor's note: This conversation has been edited and condensed for length and clarity.

Q: You taught the first diving emergency and management courses, published the first diving accident management manual, and improved access to hyperbaric chambers. What drove you to expand diver safety?
A: Before 1975, there was no recompression chamber available anywhere in all of South Florida, the Florida Keys, the Caribbean, Central or South America. The first one was built on Virginia Key, Florida, and I was the director.

We were getting divers from all over the world. A lot of these people were coming in by air evacuation. The medical director, Dr. Morgan Wells, and I began to see divers having very bad outcomes after treatment because they did not receive oxygen during transport to the chamber. Some of the local divers were getting oxygen in between transport for, you know, the three or four hours it took back then to get recreational divers to chambers.

In 1975, the NOAA director, Dr. Morgan Wells, put together a group comprised of diving medical specialists from the Navy and Air Force, and came up with the first protocol for field management of diving accidents. Lowenherz got a NOAA grant to establish a three-week physicians dive medical training course at my NOAA chamber, where we used the manual. It was also distributed publicly. After people started administering oxygen during transport to the chambers, we saw a big improvement in outcomes.

Q: Of all the ways you’ve shaped diver safety, what do you view as the most significant?
A: The increased use of oxygen-enriched air, or nitrox. There are two reasons. First of all, when you put oxygen in the air you dilute out the inert gas, that’s the nitrogen. Nitrogen is the mixture of many different gases we call nitrogen. And by diluting up the nitrogen and have made we have less narcosis...and we're and we have less of a chance of getting decompression sickness.

Q: You launched that first nitrox diving course for recreational divers in 1985. Why did you decide to bring nitrox to the recreational community, and why was that a controversial move?
A: Well, because I was a little bit more intelligent than most of the other people. Because if I put anybody out there at 130 feet on air and they got bent, they should have legal recourse against me because that’s not the best gas mix...If I use the 32 Nitrox Mix, 32 oxygen, at 130 feet, and I decompress on my air table or my air computers, and I've done everything I've always done as a recreational diver, my body’s inner gas uptake would be as if I was only at 107 feet, not at 130 feet.

Scientists thought it was just too much for other people, that the recreational divers are incapable of doing it. But we don't put the mixing and so on in the hands of the recreational divers. We just let them use it.

Q: Your career has taken you literally around the world, from the north to south pole and just about everywhere in between. Where is your favorite place to dive of all time?
A: In 1985, I did take a group of doctors and nurses from the NOAA physicians course to Truk Lagoon, Micronesia. It had nothing to do with education credits or anything, just a bunch of friends.

Q: What has been the most unexpected joy of the career path you followed?
A: I’m grateful to have been in the right place at the right time. When I was starting my career, recreational diving was in its infancy, and being in the government I had the opportunity of having great mentors I worked with for years.

Q: What has been the most gratifying aspect of your career?
A: Being able to treat over 1,200 patients, mainly at no expense, in a hyperbaric chamber, and conducting 570, 40-hour diving and clinical hyperbaric medical seminars that brought the latest diving science to 8,400 medical students.

Q: What advice do you have for young divers who want to make a career in the scuba world?
A: Get an education in a field related to the oceans that isn’t marine biology. The only two organizations that hire marine biologists are universities and government agencies. The registers are full of thousands who want to be a marine biologist, but there are 100s of other marine oceanographic scientific programs that they should look into and still have the life of the oceans. You’ve got meteorology, you’ve got the depths of the oceans, you got the salinity of the water. I've been on programs where you do subsurface work, meteorological work, oceanographic studies, and atmospheric studies and all kinds of different things.

Q: What’s next for you?
A: I started another program — Therapeutic Oxygen Health Salon, which offers oxygen therapy. You can come in and breathe oxygen for half-an-hour. That’ll recharge your cells that are not functioning properly, it’ll recharge and let your DNA replicate more. In general, it will just keep you healthier and so-on. It should help you get away from all these nonprescription healthy and beauty products you see on TV all the time.