SEP 2017: Having finalized this interview for publication, in a little more than a month, I will be traveling to Florida to meet up with Bill Stone and the Stone Aerospace team who will be conducting their second trail of the first autonomous cave diving robot, SUNFISH, in the Wes Skiles Peacock Springs. This guy never lets up!
FEB 2013: As I reviewed this interview from the aquaCORPS archives, engineer and inventor Dr. William “Bill” Stone and an international team of explorers dubbed the “U.S. Deep Cave Diving Team,” were headed back to J2 in Sistema Cheve in Southern Mexico to push beyond Sump 4 (-1484m), which at 11 km in is the most remote point inside Earth ever reached by humans, to the core of the Sierra Juarez, using modified versions of Stone’s MK-6 rebreathers. During his last expedition to Cheve in 2009, his 63rd international expedition, Stone and team spent 19-days underground reaching the sump. This time, according to 61-year old Stone, who spoke to me days before he left, the team is preparing to make a 30-day extended push to get to the bottom which may exceed 2500 meters.
Stone’s obsession to push the depths of the Earth, while inventing and building the technology to make it possible, has been a singular defining passion of the unstoppable explorer for nearly four decades. Not limited by terrestrial constraints, his company, Stone Aerospace (his “day job”), is also pioneering the development of digital mappers and autonomous unmanned vehicles (AUVs), which have been used successful in Wakulla Springs, Cenote Zacatón, under the ice in Lake Bonney in Antarctic, and are slated to be used by NASA in the coming decade to explore beneath the ice on Juniper’s frozen moon Europa as once envisioned by prescient sci-fi writer Author C. Clark.
Here, in this original Jan 1994 interview reprinted from aquaCORPS N7, Stoned, who holds 16 patents for life support, underwater and robotic systems, and was once rejected as NASA astronaut candidate talked to me candidly about his early vision to plumb the depths of Earth, as well as reach outer space. At the time, many regarded it as a fanciful notion.
Stoned: Interview with Dr. William Stone
Having descended on the diving world nearly ten years ago, caver and engineer Bill Stone, 41, has blazed a trail that has left people reeling in amazement. Definitely mind-expanding stuff.
Jokingly known as the “Barnum and Bailey” of diving to friends and cohorts, his larger-than-life productions have captured the imagination of a generation of divers and served a pivotal role in the development of self-contained diving. During his milestone Wakulla Springs Project in 1987, Stone and his team explored over 2.3 miles of underwater passage, logging more than 450 dives at depths ranging from 260 to 320 feet (80-98 meters). In the process, they helped pioneer the basic tools of modern technical diving: open circuit mix diving, long range DPV’s, a variable-depth decompression habitat or “microbell”, and Stone’s first rebreather. All this before mix diving even made it to the closet. Take another breath.
But Wakulla was just a stepping stone in Stone’s grand scheme: bottoming out the Huautla plateau system in Central Mexico–his consuming passion for more than 20 years. Threading their way through twisted miles of dry cave, subterranean rivers, waterfalls and sumps, Stone and company have descended to over 1350 meters in an attempt to connect the San Agustin entrance located on the top of the plateau to the spring that flows from its base. By their estimate, the team has another 350 meters to go to reach their goal, which would make Sistema Huautla the second deepest cave in the world. Their final push is schedule for February of this year .
Photo courtesy of William Stone and the US Deep Cave Diving Team
When he’s not dangling 200 feet in the air on a practice line, or pumping out “counterlung simulations” on the Cray-1 computer that he has convenient access to at his 50-hour a week real job at the National Institute for Standards and Technology, Stone is busy chasing down funding for his company Cis-Lunar Development Labs, which will eventually manufacture his closed circuit rebreather. And if that were not enough, he still finds time to dream about “what he really wants to do when he grows up”. A subject he’s a bit hesitant to talk about for fear of raising too many eyebrows.
The term “space cadet” takes on a new dimension when the moniker is applied to Bill Stone. Not bound by terrestrial constraints, Stone has set his sights high—about 208,000 miles above the earth to be exact—towards one of the five Lagrangian points that represents a stable gravitational point between the earth and its moon. His long-term goal is to apply the technology that he and his team have developed to put a privately funded team into orbit. Far fetched for mere mortals to be sure, but judging from Stone’s verve, imagination and drive, it’s a proposition that might just fly.
Perhaps the power of men like Stone lies in their ability to dare us to greatness–the ability to look out into that immensity that surrounds us and ask, “Why not?” Stone made a decision to touch the frontier, and in doing so, he has allowed each of us to touch it as well, if only vicariously. In the long run perhaps this will be judged as his most important contribution.
aquaCORPS:We’ve been talking about doing this interview since 1990. It’s been a long time in coming.
WS: Maybe now the time is right. You’re an established editor and I think I know how to build a rebreather. I suppose you’ve heard the classic about a couple of people who came in last year and someone asked them, “Oh, are you going closed-circuit diving today?” and they said, “No, we’re going bubbling.”
Bubblers, a new term?
The new term for open-circuit.
You’ve been working on it for…
Nine years? I can relate to that. It takes a lot of work to create something.
Fifteen years of hard work is equal to an overnight success.
I’m sure that there are many people out there who think that you are probably crazy or stoned to do some of the things you’re trying to do.
The attraction is exploration and it’s brought a whole team of people together. They want to use this device to do something that’s really going to be provocative if you will, for lack of a better word.
Capture people’s imagination?
Including your own. If you’re not doing something that’s out on the edge, and by that I don’t mean dangerous, I mean something that captures your imagination, well…? It’s like: “My God, here’s a challenge that heretofore has never been done, that has never been contemplated and we just might be able to pull it off. That’s not going to happen until we know we can do it safely – that’s why it’s taking us so long. I don’t want to bite the big one just to say that I used a rebreather.
You’re headed for Huautla.
We’re on for February 2 , the kick-off date. In fact, a lot of the crew is going to end up arriving over here in the middle of January for two weeks of chip soldering and software burning. The software is always in a state of flux. Every year for the past three years it’s happened this way. Push, push, push and finally you get the software burned. It all happens two days before you’re supposed to leave town and everybody’s sitting up at 1:00 in the morning with micro-fine soldering irons putting chips on the fucking computer boards.
Just-in-time expeditioning. Does that mean you’re funded?
We’re 90% there. The hard road has been taken care of. We’ve got the rigs in an operational state, we’ve got all the transportation arranged and the political clearances in Mexico are being taken care of right now. In fact, we’ve got negotiations going on with the Governor of Oaxaca all the way up through the Foreign Affairs office in Mexico City.
You need clearances?
With a project of this magnitude, you do. What ends up happening is that you drive down to the border with a caravan of six trucks filled with gear. The border guards pull open the sliding door on the back of the truck and go, “Whoa” and immediately they think they’ve got an opportunity. To avoid that kind of stuff we get prearranged clearances.
You’ve been going to Huautla for along time.
I started caving in high school in 1967. I heard about Huautla a year later. The story goes back to 1964 when Bill Russell at the University of Texas in Austin was looking at military topo maps for Mexico hoping to find the deepest cave in the world. You can do a lot of the analysis with maps and when you think it adds up to something deep you get in your truck and go and take a look. That’s what he was doing when he found Huautla.
Four years later in ’68, a joint Canadian-American expedition set the Western Hemisphere depth record, which was like 600 meters (1960 linear feet). In those days that was just phenomenal and everyone, including myself was just blown away. “My God, they’re that deep underground.” To give you an idea of how things have changed, we’re now shooting for 1700 meters (5575 feet).
Photo courtesy of William Stone and the US Deep Cave Diving Team
Seveteen hundred meters will put you at your final camp?
No, that would be the entire descent from the highest entrance to the springs—we haven’t made that connection yet. That’s what this whole expedition is about. We’ve reached 1353 meters from the highest entrance to the sump. That’s our dive site.
When did you finally make it there?
I found myself in Austin, which was the hotbed of expedition caving in the Western Hemisphere in the seventies. People came from everywhere to that town to organize, head for Mexico and go deep. That was the driving force in the seventies: depth, depth, and depth. When we got to Huautla in ’76, we found abundance. They had missed everything in ’68 and the earlier expeditions and of course the gear and equipment had all changed. Looking back, it was a little like the argument for [Sir Edmund] Hillary and Norgay – some people say, “Well, it’s not that big a deal to put 60 people on the summit now on a good day in May.” That didn’t make it any easier the first time.
There’s learning curve.
We sent our first three-month expedition down there in 1979 and it felt like we were going to the dark side of the moon. We set Camp 2 at a depth of 500 meters, moved on from there to Camp 3 at 800 meters. That was our game for the longest time: depth, depth, and depth. We were underground for 17 days.
A classic Huautla story. We went down there planning a 12-day trip. We left on March 5th. Nobody had Rolexes with dates and that kind of stuff; we had Mickey Mouse watches. It was like, “What time is it?” “It’s 12.” Great. Is that a.m. or p.m.? Well, I’ll just write that down as 12. We went through twelve motions of having breakfast and dinner, and we realized that we would have to bail because we were out of food. We got back to the surface and there was a note on the table dated March 22nd and we said, “Naaahhh. We couldn’t have walked five and a half days.” Finally a teacher comes over and says. “Where have you guys been?”
We lost five and half days of our lives there. Everything was dilated. We were up sometimes for 40 hours, really not even noticing it. If you try to stay up for 40 hours on the surface, you’d be trashed. Of course sometimes you come back and sleep for 20 hours without waking up, which again is bizarre. That’s all history now that people have date watches; everything is semi-cued to the surface. People prepare their departures so that they return at dawn and have some nice sunshine to dry their clothes off because they haven’t seen so much [sun].
Photo courtesy of William Stone and the US Deep Cave Diving Team
Is that when you started cave diving?
Yeah. I was introduced to cave diving in Texas using a single tank and regulator to dive flooded tunnels. Fortunately for me, a fellow by the name of Mike Boone, who happened to be one of the archetypal cave divers in Britain in the sixties, came down, heard what I was doing and said, “Do you want to survive?” And I said, “Sure.” “Well, then get a second set of tanks and wrap them on your hips like this.” That’s how I learned cave diving, British side mount style, which was an anathema to what was being done in Florida, a whole different ball game. That’s what I started using in Mexico.
When we went back down to San Agustin in ’79, I had these two tiny little 15-cubic foot buddy tanks. I got about 150 feet into the sump at a depth of about 40 feet and I was looking into this gigantic blue void and went, “Whoa. I don’t think we’re going to make it with these little things.” That plagued me for the next two years. God Almighty, this was the deepest point in the system. We were trying to break a world depth record and the only way we were going to get there was to follow this thing down until it turned around.
Is that when you got [Sheck] Exley involved?
I wrote to Sheck that next summer and said, “ I need to learn about deep diving. Will you take me on?” He said, “Jump on the plane, man.”
I went down there and he said, “The method by which you acquire depth is to go through a progressive series of exposures on compressed air.” So that’s what we did. We went to 40 meters, 50 meters, 60 meters, and our next dive was going to be Eagle’s Nest. He pulls out an oxygen bottle, which was absolutely alien to me at the time, and I said, “What’s that for?” He says, “With these, you can go real deep.” Man, I was going, “Uh oh, I’m in trouble.”
The next day we go blitzing down Eagle’s Nest, and I’d learned on the course of the previous dives that if I paid attention to what I was doing, as opposed to just looking at the instrumentation, the better off I was. That was the game, that mental concentration, knowing exactly where you were and how impaired you were. Guys like Tom Morris and Sheck Exley would come back from a dive and say, “That was great.” And we’d go, “Right”, I’d look at them and say, “You were buzzed down there, weren’t you?” “You bet your sweet ass I was.”
That’s exactly what happened to me. We got down to 240 feet (74 meters) on the way to the Super Dome or something, and Exley gives me the thumbs-up and OK. I turn around and the old delayed psycho-motor response syndrome that you get with narcosis was taking its toll and I never bothered to hit my BCD to pull myself back up. At that point I was coasting down at about 200 on the port side of narcosis and hit the mud. Splat. One great stroke and the whole place blacked out to zero visibility and this mushroom cloud that was probably eight feet in diameter engulfed me like a small atom bomb.
Exley and his partner were about 20 feet (6 meters) above me in the tunnel watching with some amusement wondering what the hell I’m doing – we gotta teach this boy some technique. Meanwhile I’m going, “Oh, jeez, I just lost a guideline,” and the old heart starts to pound and I start hyperventilating and the narcosis builds up and all of a sudden I’m on the other side of that little nice edge and I’m going, “Uh oh, I fucked up.”
Next thing I remember is that vicious little cycle that goes, “I can’t find the line, I screwed up, oh jeez, where’s the line? I screwed up. I can’t find the line.” And I started hearing this thundering locomotive type echoing of all the bubbles going off and tunnel vision starts setting in and the next thing I know I see this hand coming through the blackness and I go, “I better grab it.” And I grabbed it and Exley pulled me up about 25 feet and maybe 30 or 40 feet back down the tunnel and all of a sudden, bingo, I snap out of it and I go, “Man, what happened?” He signals, “There’s the guideline, let’s follow it out.” Everything goes perfectly from then on and Exley’s as cool as a cucumber. We get back up on the surface and he says, “Tried your limit?” I said, “Yeah, I don’t think we’re going any more than 200 feet when I get to San Agustin.” That’s where I set my limit. Exley saved my life.
You’ve been called the “Barnum & Bailey” of diving – your projects are like a three-ring circus. Talk to me a little about some of the logistics at Huautla.
We spent a year finding people who could cave and dive and another year rehearsing all the techniques that we knew we would have to deal with. Transporting camping equipment including freeze-dried food and sleeping bags through underwater tunnels and then planning on setting long-duration camps on the other side. We were the first ever to do that. It was a very intimidating prospect. We didn’t know what difficulties we would have.
To give you an idea, we carried 8 tons of equipment on our trip to explore Pena Colorada canyon. We hired 190 Indians to work for three and a half days hauling all our gear down a mile into the canyon with 60 burros and another 50 Indians to chop out a 100 by 50-meter area in the jungle. It was so dense when we got there, we couldn’t even put up a tent. We spent three months in that 150-meter canyon diving up toward San Agustin from the bottom. In the process, we ended up pushing through seven underwater tunnels (sumps) with 72 composite tanks supplied to us by Accurex and Sherwood. The classic siege using pyramid logistics.
You start off with seventy-two scuba tanks which you haul into the cave to get to the first sump. You use up a dozen to get through to the other side and then you start hauling them to the next sump. Now you have less tanks so a few people have to drop out. You got through to the next sump and trash another dozen tanks out of the plan. And on it goes. We kept doing this until we were left with two support personnel and two divers and four tanks. At that point we were four-and-a-half kilometers into the mountain about 25 percent of which was underwater. That was our final dive. We did that three times, hauling all the tanks in, pushing further and further and further each time, then hauling them all back to the compressor and doing it again. The final obstacle was a real nightmare.
We knew we were going up because we were at 300 meters deeper in elevation than the bottom of San Agustin, the bottom itself. From the way the geology works we were eventually going to get through to airspace, we had worked al the hydrologic flow calculations. So we had 300 meters of elevation and we were scaling shafts for quite some time. At some point we knew we were on to it; things were really going good and bingo, one fine day, the guys are walking down the passage and there’s a hole in the floor 20 meters in diameter. A great big tunnel going down. We throw a rope in and 60 meters later – a 200-foot free fall – guess what? Another dive. There’s no ledges, no nothing, no place to put your diving gear, so you have to put your tanks on at the top of this damn thing and repel 200 feet down and free fall into the water. That was Sump #7. Needless to say, the troops said, “This one’s yours, Stone.” We were there for three months and we pushed the logistics of open circuit technology to the absolute max. There were some great stories on that trip.
Is that when you started working ono your closed circuit system?
Yes. We got back from our trip and were scratching our heads. Noel Sloan, and M.D. John Zumrick, who was the Chief Medical Officer at the Navy Experimental Dive Unit and myself. Zumrick who was infinitely familiar with the Mark-15 and Mark-16, which was still in development, said, “What you need to do is start looking at closed circuit technology if you want to have any chance at all of finishing this project.” That was it.
I spent all of 1984 doing research – that’s my bag professionally. The next year I spent a great deal of time at the Navy Experimental Dive Unit (NEDU) in Panama City tearing apart the Mark-15. I just kept going through the beast and the manual until I knew it from rote. Once I had a handle on the system, the next step was to modify it to get it to do what we wanted. The problem with military rebreathers is that they don’t have sufficient redundancy. You cannot use them safely for cave diving unless you have a lot of peripheral bail out equipment.
I immediately had 36” drawings made up with our modifications and gave our big spiel to Biomarine. They said, “This is really interesting, let us think about this.” Three weeks went by. Four, five weeks. I finally called them up and they said, “Well, we think your idea’s really interesting and we’d like to help you out. But the best way for you to do it is simply to buy a couple of rigs.
Back to the drawing board?
Our initial designs were essentially oddball spin-offs of the Mark-15.5. I had to spend the time to find out that it just wasn’t going to work and realize I couldn’t turn a pig’s ear into a silk purse. My next steps were to start reading up on physiology and everything related to control systems, which was new to me coming from structural dynamics. I also had to start picking up a lot on the mechanical design. It’s really an interesting problem because of the trade-offs between buoyancy and size; anything large enough to do what we wanted closed circuit-wise had buoyancy problems, so you start adding lead, and end up going full circle. Eventually you find yourself doing very serious optimized structural design to minimize the volume and achieve the desired functionality because the volume controls the system’s buoyancy.
Finally in the fall of 1986, I gave a talk on my ideas. Everybody sat there and listened politely to my structural notes and statistical probabilities, and they said, “This is very cute, Stone, but you’re going to have to build it and prove it to us.”
All told it took three years to actually “bend metal,” as the aerospace people would say. The result was what I would call the Mark-1 and it was this 195-pound behemoth. I’ll bet it was the first diving apparatus – life support system – that has ever been statistically designed to be fault tolerant from the ground up. That’s what controlled the architecture. I wasn’t too worried about compactness initially. Our approach was to get the functionality into the system and try to see if it worked. Then we could start thinking about optimization. Long before that, we had begun writing the microprocessor control program. By 1987 we had an operational system driven by four onboard processors. That was the unit we tested at Wakulla Springs, FL.
Photo courtesy of William Stone and the US Deep Cave Diving Team
Exactly. We needed a good clear water site that had variable depth to around 300 feet. The State of Florida had just acquired Wakulla Springs and it seemed like an ideal location. So I immediately called up Sheck and Paul DeLoach and said, “Hey, guys, I’m putting together a proposal to do scientific research on life support systems at the spring. Do you want to put a rider on to do some simple exploration?” And they said, “You bet.” So they helped me write the exploration side. In fact, DeLoach, Zumrick and Mary Ellen Eckoff had been the only three people ever to dive in that spring legally until then.
I submitted our proposal with the primary objective being our work on closed circuit systems. The second objective was to do a little exploration. The State got back to me and said, “This proposal is extremely intriguing and we would like to follow up on this. However, we feel that your priorities are in error. We would like to see exploration be first.” At which point I was going, the sky has just opened up and rained bread. Those boys in Florida are going to have their day. I called them up and said, “Guess what?” That was the fall of 1986. In December we got the go ahead on the project. We eventually got started the following October.
Didn’t you get involved in the Andros project with Rob Palmer and Stuart Clough about the same time?
The project was based on Pete Art’s geological project out of the University of Bristol. The objective was to go down there and collect deep stalagmitic material which contained uranium records of the date at which the ocean level receded to that point. Palmer and I had done some trimix diving at Wooky Hole. Emboldened by our success, Palmer launched the International Blue Hole Project. I was the U.S. coordinator.
Originally, we were going to bring the Mark 1 to Andros, because we were expecting the site to hit 500 feet. However, by springtime I was heavy into Wakulla and the rig design was falling further and further behind. Palmer was insistent. “We’ve got to find a rebreather somewhere,” he said. It just so happened that Palmer caught a British PBS program called Beyond Tomorrow or something. Lo and behold there was Stuart Clough on the telly with his Mark-15.5 making a chamber run at Fort Bovisand. It was the first time any of us had heard about his system. He made the call.
That was your first closed circuit operation?
Right. We only had about ten days of rebreather diving before the Carmellan crew had to bolt. There we were with a ton of heliox and open-circuit equipment so we had the chance to do some serious open circuit heliox dives. Our thinking at the time was “Why screw around with trimix?” We wanted to be levelheaded at depth and stay frosty. We had work to do. We limited ourselves to 40 minute screamer dives to 300 odd feet/92 meters; with the five hour decompression penalty you’d freeze your ass off in the 78 degree water in that amount of time. For the next month we dived, took data and collected stalagmites. We were on a roll. That was the set-up for Wakulla.
Wasn’t that your tie-in to Dr. Bill Hamilton as well?
That was the key connection. Hamilton had been working with Stuart Clough and showed up on Andros. As soon as we met we established this nuclear bond. I said, “Man, we’ve got a project going on this fall which you should be involved with.” We ended up going down two parallel paths. I worked with Bill and the NEDU to generate tables based on Buhlmann’s algorithms. Our goal was to cut down the decompression time by taking a radical approach on gas switches. So Bill came up with the now well known idea that you go down on heliox and then come back on various nitrox mixtures, including air in the habitat, and then O2.
History in the making! Wakulla obviously came off well and you spent 24 hours underwater on the Mark-1. What was your next hurdle?
After Wakulla, the prime motivation was to redesign the Mark-1. Although it was ungainly in weight, it had outrageous range. Our next challenge was to get the Mark-2 down to 130 pounds. We did that. Then we began tackling all the little operational problems. We did a good bit of diving on the systems in the fall of 1989 and then it kind of languished. That was the point we brought in Richard Nordstrom as CEO of Cis-Lunar [Cis-Lunar Devlopment Laboratories Inc.], pulled in a couple more engineers, and then things took off. It’s been refinement after refinement ever since.
Has it been just a matter of resources? If you had a couple of million in the bank could you have done it a lot quicker?
Even if we had the money…. It’s been an extremely painful process. We’ve got probably 25,000 man-hours if not more into the design of this rig. We’re now up to the Mark-4, which we were diving this spring, but the changes that went on between the Mark-2 and the Mark-3 were immense. Architecture, reliability, functionality – we really started to learn what the hell we were doing with the Mark-3. The jump between the Mark-2 and the Mark-3 was as great as the difference between the Mark-1 and nothing – a huge difference in terms of operational capability. We took the Mark-3 down to Jacksonville in the spring of 1992 and spent six weeks putting it through its paces. Everybody came back with a ten-page list of “fix this and then we’ll have a great system.” We spent the next ten months doing just that. Sixteen thousand lines of code later we had the Mark-4. It’s gotten to the stage now when I’m diving, that I’m not even thinking about how many solder joints are in the computer system.
How does the Mark-4 differ from other rebreathers on the market? What makes it unique?
The main effort was put into the work of breathing. That’s the most critical aspect. Forget about controlling gas mixtures and things like that for a moment. The critical question is can you breathe on it underwater? A poorly designed rebreather will breathe like a dog and require tremendous amounts of work to inhale or exhale. It all depends on the counterlung or breathing bag. The position and geometry of that bag are the difference between night and day, between a Chevy and a Cadillac, actually a Chevy and a Ferrari would be a better comparison.
Most of the systems on the market seem pretty much the same with regard to breathing bag design.
That’s right. For example, a pure oxygen rebreather has a breathing bag that sticks out on the front of your chest and tends to have a very high positive inhalation pressure. It feels like to wants to blow the frigging regulator out of your mouth. The other side of that coin is the Mark-15/16 type system that has the bag on your back. It’s the opposite; you have to work to draw the gas into your lungs. From a physiological perspective that’s much worse than the situation imposed by say the front mounted Dräger LAR-V which is used by US Navy combat swimmers. Your lungs prefer to be loaded inhalation-wise as opposed to exhalation.
The way you can tell that is to blow up a balloon. It’s easy, right? Your lungs really don’t complain too much. Now try taking a plate and sucking the plate so you can hold it by maintaining the vacuum. Your lungs are screaming. Lungs abhor a vacuum. That’s effectively what you have to do to pull the gas out of a Mark-16. Every time you breathe you’re doing that Delta H transfer of mass into your lungs. What’s more is that this workload can be modeled as a sinusoidal curve.
I’m giving you Rebreather Design 101; I’m not going to get too much in depth here. Suffice it to say that you can create a computer design program to investigate all the possible shapes of the curve to meet the needs of the human body and get it within a very, very tight tolerance of the desirable threshold pressures. That’s what I did in 1988 to come up with an optimized shape for the counter-lung. That was the basis for our patent. We utilize a split counterlung that fits over each lung and shoulder. It’s fundamentally different than other designs.
The next generation?
We also have spent a lot of time looking into things like manual control systems. If you need to get at your gas controls on any of the existing military units, you have to reach way back and find the buttons. That’s the situation that we had at Andros, the manual controls were a dog. So we came up with this idea of completely re-routing all the control systems into something that can be easily grabbed by one hand. We tested that idea with the Mark-1 and it looked like the space console.
I remember the pictures.
Eventually, we condensed that down to compact size and mounted it on the front of the rig, so that the operator has complete control for directing oxygen flow, directing gas flow, shutting off various systems in case of a problem. This was all mission-driven by cave diving.
In fact, the whole system was designed to be fully redundant in the closed-circuit mode and fully field configurable. It’s modular. The diver can say, “I understand how this module works; I’m going to repipe this, I’ll put this over here, I’ll reorient over there, I’ll put these bottles over here. Now I’ve got redundant gas supply.”
We’ve built one or two kilometer range systems, highly efficient in closed circuit mode with a pretty slim likelihood of anything going wrong. If it does you can go on open circuit bailout. With a single configured unit we don’t go any further than our bailout can cover. Or you can configure a fully redundant explorer mode with completely dual systems for long distance runs.
You’re saying you can actually re-configure the rig based on the type of dive you are going to do?
And if you find that you’re getting beyond that range, you come over, strap another module on to the backpack, redo the connecting pneumatics – it’s fairly straightforward because it’s all flexible. And bingo, you’re off and running.
I understand the mouthpiece that you’ve developed is pretty trick. [Ed. Note: Integrated open circuit Bail Out Valves (BOV) are now standard
On many rebreathers]. We spent a lot of time designing the mouthpiece and have several patents on it. You can throw a switch and you’re in open-circuit mode. For example if you had as catastrophic failure and needed to switch systems in a double-rig, you would simply throw this thing into open-circuit, blow the gas out, take breath for the transfer, grab the second hose which is idling in open circuit mode, and blow into that. If you need another breath you’ve got a breath and when everything is copacetic, you switch back and you’re on system #2. You simply acknowledge to the computer that you’re active on the new system, it carries your decompression and away you go. Once you’ve gotten into the habit, you realize how easy it is. The time pressure goes away. If shit hits the fan, you’ve got another eight hours – eight hours!
What’s it like doing your own test diving?
A classic story. We get to Cueva Inferno, which literally means “cave from hell” in Spanish, and we’re down there in this very spooky place – a 20 meter diameter dark brown tunnel leading down into this underwater pool.
To make a long story short here, each diver was putting their system together and methodically going over everything. Double-checking it. Triple-checking it. Finally they’re ready to go and Noel Sloan leans over to Lee Porter and says, “Scoop bootie brother,” which in caving slang means, “Go discover a virgin tunnel.” And Porter, who was looking at his LED, says, “I’m going to be taking this slow,” which in essence meant, “This is an experimental piece of apparatus and it’s on my butt, and I’m in some godforsaken remote tunnel at 3600 feet elevation and there’s no chamber and it’s going to take a week to get me to a chamber if I needed one and I’m going to take this slow.” Of course they took it real slow, and had a nice dive, but the point was that it was for real. We knew what the difference between reality and simulation meant right there. Everybody had a chance to experience it. Boy, it was sobering.
The main mission driving all of this is that it’s got to be super reliable to be able to be used for cave diving. So if anything goes wrong at any point, it’s no sweat. It’s like, “So what; we’ve got another eight hours.” That’s the thing that kills cave-divers. If you look at the records over the last ten years there’s probably 50 or 60 people who have died – it’s largely due to panic. Or a situation where the diver gets himself into a corner where time becomes the critical element.
The classic example where a man had all the right stuff and didn’t survive was Parker Turner. There was a guy who runs cool as a block of ice, and nobody else to my knowledge besides his partner could have done what they did (see “The Accident Report from Indian Springs” by Bill Gavin, Technical Diver 3.2 92OCT). They were trapped in the cave for an hour and a half at 140 feet/43 meters with limited resources, trying, trying, and trying to get themselves out.
Photo courtesy of William Stone and the US Deep Cave Diving Team
The fact that Gavin got out was a testimony to their cool.
They remained cool to the end. It was not in their minds to panic. That was proven clearly. But if they had a system that was not as sensitive to range the way open-circuit equipment is at depth…. The point is that when you go to closed circuit, all that goes away.
It’s going to change the whole mind-set of diving.
We’ve spent the last four years honing the mechanisms such that the likelihood of failure is extremely small, even if you’re a real jerk. The system can tolerate flooding. No one else’s can to my knowledge. For example, when we were out on Andros in ’87, it was understood that if your mouthpiece came out and you put it back in and heard gurgling, that was it. You had to go for your bailout and get the hell out. That was the bottom line. We can recover from a full flood on this thing.
You can recover from a floodled canister as well?
Yes, it’s part of our patent. Hang around tomorrow and I’ll give you a demo. As I said, we’ve tried to build these systems so that you can abuse them and then still have them work. We saw lots of abuse this past spring. We logged 166 missions on the rigs, almost 300 hours of underwater time at depths down to 80 meters.
You have to understand, these guys don’t view this thing as some holy piece of equipment, but rather as a utilitarian chunk of hardware. That was the big change that took place this spring. That’s why I say this was the threshold year. The bottom line is that the system has the redundancy that we felt was needed. It’s gonna be our asses with a backpack on them.
While we’re on the subject of safety let me change topics a bit. How high do you run your PO2s during operations?
We typically used a 1.0 set point. We’ve had a lot of philosophical discussions about it. Carmellan has played around with 1.3 and 1.4. I might also add they’ve been known to have problems. One of them had an O2 hit a couple of years ago due to a solenoid that failed in open position and dumped a lot of oxygen into the system. The fact that they had been running at 1.4 for a while most likely contributed.
Spiked their PO2?
The problem is that your body gets loaded and when you push it up you’re much more sensitive to a spike than you would be if you had been running at 1.0.
Richard Vann at Duke University told me that he’s had a lot of direct experience with oxygen rebreathers. [See “Oxygen Tolerance Management” by R. Vann, aquaCORPS, n7 C2, pg. 54] Apparently military divers have had problems with spikes – sudden depth changes. Apparently the enzymes that protect the body from high PO2s get used up and then the spike hammers you. At tek last year he gave a talk and people asked him how high he recommended running working PO2s. His recommendation was 1.2, which nobody wanted to hear.
It’s interesting the Navy is backing down to a PO2 of 1.3 and you’re saying Vann wants 1.2. We’re already at 1.0. I guess we’re leading the pack.
I’ve heard a lot of people say that your system is just too big.
We could make the system a lot smaller if it was purely a sport unit. We’ve had to leave space to allow the divers to configure into an explorer model. We’ve also oriented the stack (i.e. canister) horizontally to reduce the vertical height of the unit. That’s one of the reasons it looks so different. Once we get away from the cave-diving/ mission-driven scenario model, we’re probably going to be able to reduce the size by 30% and cut the weight by a factor of two. Yeah, everybody’s always on me, “It’s too heavy, Stone, get light.” We’ll get there.
How about training? How long will it take for someone to train to dive the Mark-4?
If you’re an advanced diver I could get you off and running in about ten hours. With the double rig it takes more like 20-25 before you feel reel comfortable with it.
How much of that is emergency procedures, knowing what to do when something goes wrong?
Almost all of it is. Like telling someone they can be a co-pilot and you get up in the air and say, “OK, you fly.” And the guy says this is pretty cool I’m flying. But is he landing? Is he taking off? What does he do if you tell him to vector north because they’ve got inbound traffic? Things like that. It’s got to be taken in steps.
We’ve been talking about a lot of capability that will be available to support diving operations in the future. What will technical divers be doing 15 years from now in diving?
People will always be bold. Exley is about to do a 300 meter dive. There’s a man who’s got focused mission. He simply uses technology that he’s comfortable with until it can’t go any further and he’s bound and determined to crack 300 meters. I hope he does it. He’ll be the first human to do a surface-to-surface 300 meter dive. I wish he was using a rebreather. It would eliminate a lot of the reliability factor. That’s what happened to Hasenmayer. He was rehearsing for a 300-meter dive in a Swiss lake. He had a regulator malfunction and had to omit decompression on several stops. As a result he ended up getting a helium hit and was paralyzed. Sheck is a dear friend and we go back a long way. If anybody can do it, he can. The guy has got such control; in fact many people believe that he is not human. Eventually, I’m going to talk him into rebreathers because it’s really the way to go for the stuff like that.
Where will the real cutting edge be in 15 or 20 years?
I think we’ll be doing 1000 to 1,500 foot dives (300-460 meters) off a wall on hydreliox. We’ve learned enough tricks with what we’ve done with the Mark-4 to easily build a hydreliox machine on your back and make it work. You’ll go out there and blow your stacks and skydive down to 1500 feet off the wall, re-blow, bounce back up and probably get yourself a five to seven hour dive if you do it properly.
Of course, rebreathers aren’t going to get us over the decompression hurdle. Unless we come up with something new, we still have that barrier to deal with. That forces you to go to unusual regimes if you’re going to do something unique like applying commercial methods. We’ve already had discussions of putting a habitat at 250 feet (77 meters) inside the main tunnel at Wakulla and using that as a transfer station to bring the guys out. They’ll go down, do their mission, come back to the habitat which will have its own environmental control system. I can do that right now with the control system on the Mark-4. I can drive the habitat to maintain that depth.
So you’d put them in saturation?
They’d come back, lock-in to a transfer capsule and be hauled up to the surface under pressure. You’d have to have either a crane or a gantry or some simple system that would allow you to pick it up and lock it into a chamber. They get a night’s sleep, eat, and then next day you’d transfer them back down all recharged and ready to rock and roll.
It’s done every day in the North Sea. It’s just at a different level. There’s an exciting future in store for us.
So what do you want to be when you grow up? An explorer, or the head of a rebreather company?
It all started for me with Huautla, but I guess the big change took place in 1990 when we hired a CEO to make Cis-Lunar a business. I am merely an engineer now. I really don’t have anything to do with the daily operation of the company. That’s the CEO’s job. I have a lot of input into how things might work, but there’s eight other engineers who are driving this project now. It’s taken off; it’s on its own.
[Ed. Note: Cis-Lunar Labs was put on hold during the dot-com crash in 2000 when it was unavailable to raise financing to complete its MK-V rebreather. In 2005, Poseidon Diving Systems Ltd. acquired Cis-Lunar and retained Bill Stone to help them design a rebreather for recreational divers, dubbed the Mk-VI Discovery.]
Are you still working your regular, ah, um, your irregular job at the U.S. Geological survey?
About 40-50 hours a week there and about 50 hours here.
At some point you’ll just cut it off and….
And be working a hundred hours a week….
Doing what you love!
We were here two weekends ago with the entire engineering team and that’s a pretty righteous group. The topic of discussion was the Mark-5. It’s going to be out there. Everything that we’ve learned is now going to be put into this device, fully-targeted for production. It’ll be quite different from the system we’re using for cave diving. I could work on that seven days a week.
If you don’t have a mission, you don’t tend to want to invent new technology. My role in this whole thing is being out there on the edge with the equipment, then coming back with the ideas and saying, “If we can do this, we do this! Eventually we’re going to transfer this technology into low-pressure spacesuit designs and start looking at getting private operations in orbit.
I’ve heard that you wanted to go into space.
A couple of years ago when we were really embroiled in this, trying to get Huautla done, I was feeling that I was just going to retire from all this crap. I couldn’t even think about how I was going to get from point A to point B. It was about that time I was wandering around NASA seeing what was going on, and I realized that what I really wanted to do is get a long duration group into orbit and then try to get back to earth. Unfortunately, I get myself into trouble every time I talk about that. What an arrogant son-of-a-bitch! He thinks he can put his own space program together. I just stopped talking about it.
Do you foresee the emergence of commercial space industry?
The fact of the matter is that it’s being pushed in that direction by our generous Congress which is on the verge of voting the space station out of NASA’s budget as well. That’s probably good because they can’t spend that money well enough to get the rest of us up into orbit. They have just enough money to put a few lucky astronauts up there, a week up in orbit and then they come down. How does that benefit the rest of the populace? It’s time for us grunts to take over the reins and figure out a way to get up there economically.
The final frontier.
We’re going to end up taking all the technology that we’ve developed and build suits that are basically no more than workman’s overalls. They’re going to cost about a hundredth of what is presently being paid for a one-of-a-kind aerospace product. Down the line we’ll move into spacecraft life support systems. That’s the way to go and I think we’re going to find partners all along the way to participate, just like we’re doing now.
Where do you go from here?
It’s now at the stage where the unlimited possibilities are starting to unfold. It’s just starting to get fun! I have climbed the steps and all of a sudden I’ve gotten over the rise and can see where the next steps are. The next couple of years are going to be real interesting.