Devil Gas and the origin of species
The Falkland Islands Expedition had been an adventure, I had enjoyed the wilderness and isolation of the South Atlantic, it’s wild cliffs and storm lashed coasts, the ever changing weather, (think Scotland or Northern Ireland on steroids), and the self-sufficient approach to our diving too. This was not Jamaica and the laid back sun-drenched coast, with its powder Blue Sea, it’s white sand beaches…. and “Iree“…. this was drama on a daily basis, dark and gloomy skies, often heavy and grey with Cumulus and Nimbus clouds, its rain lashed headlands and the ever changing winds, one minute gentle breezes, then an hour later whirling dervish mistral, building to storm force gales at the whim of the Gods. Truly four seasons in most days…..and this was the Falklands in summer!
The time spent there was, truly, adventurous diving, the little inflatables were tiny specks on the vastness of the South Atlantic Ocean, we were always focused on the sea-state around us and the weather reports, mindful that weather builds there very quickly, it didn’t take much to go from a diveable state to life-threatening, and change came on quickly too. Don had secured some kit deals before we left England, he had anticipated the need for rugged, easily serviceable regulators, and talked Poseidon into a military discount for those on the expedition. It gave us options, use our own regs and deco rigs, or use common expedition Jetstreams and Cyklons which Don had upgraded to when he started to use “Nitrox”. Don had to keep reasonably quiet about his Nitrox diving in BSAC circles as it was colloquially known as “Devil-Gas,” its use banned in the BSAC world since 1992. Now that had me interested, I knew the Poseidon’s were great regs, (I also knew I couldn’t afford them) here was a way of getting to use them and evaluate whether they were worth the extra £100 above the cost of most regular dive regs…. Then there was this “Nitrox” stuff…..what was all that about?
I had plenty of time to talk with Don over the 3 weeks plus we were in the Falklands and Don, outside the BSAC diving clique, was pushing limits, he had obviously been seduced to the dark side for some time now, he didn’t say when and wasn’t really forthcoming, this was no enticement, just an answering of questions whenever they came up, and, although there were plenty of opportunities, I didn’t want to be rude or feel that I was playing inquisitor. There was plenty to occupy Don running the expedition, he didn’t need me adding anything to that pressure but I had questions, why were BSAC fighting any attempt to bring Devil Gas into the fold….and why the fcuk call it “Devil Gas” in the first place if you didn’t want it to get even more coverage? Perhaps the biggest question of them all, what exactly was it and why was it nicknamed Devil Gas…….? I was a shit Padawan, I managed to push nitrox into far too many conversations to feign a “passing” interest, I wanted to know what the fuss was all about and Don was the only person I knew who had used the stuff….ergo I was his shadow….and Don……he had become Gas-Yoda! Don was keen to point out there was nothing “special” about Nitrox, he didn’t know why it had been slated as “Devil Gas” in the higher echelons of the BSAC but, privately, he wasn’t sure the senior BSAC divers were ready for anything else new, or cutting edge? I had some sympathy there, I had my own experiences when going straight for a Buddy Commando stab jacket over an adjustable buoyancy Life Jacket (ABLJ)…..I was in “too much of a hurry to embrace “new” and “potentially dangerous” kit, having too few dives to make such decisions wisely”….. as far as some in TIDSAC believed
I quizzed Don on what Nitrox was and he took the time to explain, apparently it was nothing more than a custom “mix” of Oxygen in the air we naturally breathed to dive, it was all down to percentages and something distant from my school classrooms of a decade plus ago…partial pressures……. Now I had always hated school, I hated the confinement in dreary classrooms, the bored and disaffected teachers, the stupefyingly dull subjects, I mean, Latin FFS…. (How many Roman Centurions would I ever get to speak to…?), algebra, trigonometry….statistics, God just kill me now….but most of all, the absolute epitome of mind numbingly shit subjects…… in the entire panoply of scholarship…….. was Mathematics. I have zero to the Nth degree empathy with Maths, I would rather mow a stately home lawn with my teeth than sit through a 20 minute Maths lesson…….. so the minute Don said, “…It’s simple really….the normal 79% Nitrogen to 21% Oxygen ratio is adjusted in the gas mix to give an equivalent shallower depth to that being dived….giving an elevated Oxygen level in the blood, reducing the decompression obligation or increasing the safety factor exponentially….” I just glazed over and any interest died. Don might as well have said Acta Deos numquam mortalia fallunt (look it up…)
I was not going to get any further with Nitrox and might as well admit it, it was Math related and I hated Maths with a driven passion. Figures move on a page when I look at them, they still do, they won’t stay still long enough for me to make any sense of them, I’d tried, don’t get me wrong, I don’t just refuse to take on new things, but in school I just did not “get” maths. I believed I was just plain “thick” and so did my Math teacher, I made no excuses for it either, I was happy to look him straight in the eye and tell him Math was a shit subject and I couldn’t give a Fcuk if I didn’t understand calculus or formulae….I could count and I could add and subtract, that’d do me! That wasn’t going to help me with Nitrox though, but I think it sparked some buried teaching instinct in Don, perhaps he identified with my rebellious nature, perhaps he saw something of himself in me, maybe he was just interested in a challenge, but he was clear…..”Col, even you can learn this stuff….if you want to…..It’s easy and I can teach you….if you want me to?” Now I was not convinced at the time, but I wanted to know more, I had the sense I would be near the front end of something new, for perhaps the first time in my life, and that pricked my ears up……and I wasn’t quite ready to let it go……..not just yet
So over the remaining weeks I would ask Don, “so what are the advantages of this mixed gas then”, and the answers were interesting, really interesting, Nitrox allowed you to spend more time in the water, if you took enough gas with you, it was “Gas” now, not “Air”…. Which kind of made sense as Air is a mixture of gasses to begin with, I remembered that when I first started diving from way back in Physics classes, 79% Nitrogen, 20.”Whatever”% Oxygen with the remainder “trace” elements like Argon…… So I was comfy that Air had become Gas…..I was, unknowingly being unwittingly seduced….ever closer to the Dark Side. So what was the benefit other than “more time”, because I knew some of the UK diving I was doing you wouldn’t necessarily want more than 30 minutes bottom time, UK waters were as cold as the Falklands for most of the year and, even if your core was able to take prolonged immersion, your fingers suffered, and that made operating your kit difficult towards the most dangerous part of the dive, the final ascent….no one wanted to fluff their air control and end up in a missed stop, or risking embolism on a fast ascent! Was Nitrox a “deep gas”?
I was approaching 40m dives on some occasions now, and didn’t want to end up pushing myself into something I wasn’t ready for. I was progressing at a comfortable rate, not number crunching, if a dive was good at 10m that’s where I was, if it had something great to see at 35m then fine I’d go there, but there was never a sense of let’s go deeper for the hell of going deeper, I didn’t “get” that either, usually the viz was poor and there was little to see at 35m in UK waters, why push that to 45 if there was nothing but rock sand and kelp waiting for you….? But Nitrox wasn’t that sort of Gas, increasing the amount of Oxygen in the breathing gas was actually restrictive, increased partial pressures of Oxygen (PPO2) could be fatal beyond 1.9% and the International Association of Nitrox and Technical Divers (IANTD) recommended a maximum of 1.6% PPO2 and only when a dive was considered low stress and low physical effort at that, otherwise their maximum recommended PPO2 was 1.4%, so you were actually expected to consider Nitrox a viable Gas to around the 40m mark, anyhow, and as Don pointed out, at this time you would find it difficult to get Nitrox mixes beyond 2 “standard” mixes, 32% and 36% with, if you were lucky enough to have a broad minded dive centre, 50% and 75% as ”decompression” gasses, and only then if you had an Advanced Nitrox ticket.
Now Don was leaving the Army soon, as was I, Don knew of my plans to set up a dive business once I had settled in my new home-town of Uttoxeter, and he offered to do some work leading me into Nitrox and seeing if I was happy where it would take me, before I made any commitment. That wasn’t just commitment to the learning of even more new practices and techniques, after all, I’d only just taken the leap across to PADI, and that had been an eye opener and far more effort than I’d expected (as those of you who have read the piece on PADI Training will be aware), but this commitment would see me need more investment in equipment too. Nitrox was an emergent technology and necessitated dedicated regulators, O2 cleaned cylinders, dedicated decompression rigs and the investment in training….but it was enticing, the benefits seemed undeniable, clearer decision making based on better Oxygenation during the dive, if you used Nitrox mixes on no-decompression, or “standard” bottom time dives, (equivalent Air depth diving) you were far safer, as your blood Oxygen level was higher throughout the dive, and if you wanted to use it to extend your dives, you could combine higher Oxygen percentage decompression gasses with the extended dive times, and reduce the decompression obligation so you were out of the water quicker than you would have been on Air….what wasn’t to like, I was sliding deeper towards the dark side with every conversation, I wanted to know all there was to know before I spent penny One! I wasn’t confident that even Don could teach me the math required for Nitrox diving…..but I was beginning to feel that eventual surrender to the force was inevitable…….
After the Falkland dives were wrapped up, with our last dive in Port Stanley sound on the SS Kelly 03rd February of 1996, I said my farewells to the expedition team and began the glide path to my own event horizon in June of 1996, when, after 9 years, I would be free of the British Army and have to fend for myself amongst hordes of the uninitiated….or “Civvies” as those in the services know them. I had arranged with Don to carry on with Nitrox, and to actually get into the water and try the stuff, it would be back to Stoney Cove in Leicester, and we arranged to meet up there on the 10th of March ’96, it would be cold in Stoney in March…..I wasn’t truly sure I wanted that much longer underwater if I’m truly honest……… Don took me through the do’s and don’ts before the dive, Percy, one of the divers from the Southern Craftsman expedition had decided to join us too, he had been thinking the same as me and obviously had similar conversations with Don whilst we were in Port Stanley, perhaps even beforehand…. And so to Stoney Cove, 10th March of 1996 and a series of Nitrox dives…the log book recorded: “Nitrox Dive – Stoney Cove – Leic Diving Nitrox for the First time. Spent 20 min @ 20m & went through double reel deployment drills. Certainly felt less fatigued & was “clearer” throughout the dive Viz 0-10m W/Temp 6 Air In 225 – Out 100 Buddies Don & Percy” The dive was completed using 31% Nitrox. That was quickly followed an hour or so later, following some surface code workings and Gas re-fills, and was recorded so: “Nitrox II – Stoney Cove – Leic same mix but practicing reel deployment. Definitely less fatigue & clearer thought processes. More involved dive planning. W/Temp 6’ Air in 100 out 50 Buddy Percy”
I had 10 days to learn the rest of the planning and precautions stages of Nitrox diving, then we were back at Stoney to finish off the IANTD Nitrox Diver Course, my log book records, 20 March 1996: “Freshwater Dive- Stoney Cove Leic. Finishing off Nitrox Course, planned and executed a deep dive and deco stops. Really Green hue to everything but good. Viz @ 35m (5m) practiced DV swapping for deco mix. W/Temp 4’ Viz 5m Air in 225 Out 100 Buddy Don & Mik” We had completed that dive using 30% Nitrox as it was deeper, and we needed to lower the PPO2 for the water temperature and work- loads expected. We went right back in an hour or so later this time on a 40% mix and the log again records: “Nitrox – Stoney Cove – Leic 1.5 hr surface interval – change of mix & back in – Viz good (5m). W/Temp 4’ Air in 220 Out 140 Buddy’s Don Mik Toots” This was my One hundred and Seventy Third dive to date, I was beginning to get the hang of this diving lark….and it seemed I’d never stop learning either!
There’d been Partial Pressures of gasses, Fractions of gas, Best mix calculations, Units of Pulmonary Toxicity Doses, a whole new set of decompression tables to work through, gas switches for decompression, Maximum Operating Depths, “best” Fractions of Oxygen….. and a whole host of kit configurations to look through, along with drills for deployable surface marker buoys (DSMB’s) and gas analysis, cylinder markings and gas logs to go through…. The last few months seemed to have been a self-inflicted blur of dive related learning on a scale I’d never have dreamed possible, but it had opened up another opportunity as Don had said, “you’re finding the diving easy, you’ve adapted well and despite what you said, you don’t have a problem with the Math”……..It was true, Don had approached my Maths deficiency with a degree of insight I had never been exposed to before, after the first half hour of working fractions he turned to me and said, “……..trust me….stop thinking “why”…..just follow the steps I show you every time and if the answer you get is the same as mine then it doesn’t matter “why” does it…..?” I couldn’t argue, I just did what Don said, I followed the steps he gave, slowly at first, but with growing confidence, and the figures started to match…..I was doing Math….it was nothing short of a fcuking miracle and if old “Etty Johnson” (E.T. Johnson, my form Math teacher) of KGV could have seen it, he’d not have believed it in a million years. So I’d learnt another way to dive, and I had another step if I wanted it, Don would be happy to take me on to the Advanced Nitrox Course……. if it was something that might be of interest…..? I could feel a disruption in the universe…….could I ever truly give myself to the Dark Side……
