Saturday, July 13, 2024
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Diving's Next Big Thing

I am troubled, ill at ease. I’m not even sure I should be writing about this stuff at all. I should hand it off to our estimable Scuba Editor, Sara-Lise Haith, but the story is simply too big. Too big, I say, in the sense that a stunning, epochal turn in the very flow of History is at stake. Too big, also, at eight (8) pages, which will result once again in my enraged Editor sending to me that sandwich bag stuffed with gerbil droppings, his traditional way of reminding me to serialize long articles.

No ! I shall not climb down from this monster, though it means sacrificing my stellar journalistic career at the very moment of its climactic flowering, and planting the seeds of eternal grudge against me.

I must tell you what I have learned, and I must tell it all, now, in it’s entirety, though fill eight (8) precious web pages it surely does. This is my moment of truth.

And so:

Alon Bodner has invented a radically new type of dive kit, a technology which his United States patent application blandly discloses is a “ . . self-contained open-circuit breathing apparatus for use within a body of water..”.

Alon Bodner Headshot

Now, if you work that one out it becomes, let’s see, uh…..SCOCBAFUWBOW, which is pretty different from SCUBA. Scuba diving involves those big, heavy tanks which rich tourists get helped into by those instructors with the huge muscles developed by schlepping them onto the boat, off the boat, to the compressor, from the compressor….

Alon Bodner’s deal is for people who want to dive without  bringing along those beloved (read: cumbersome, heavy, damned) aluminum 80’s or any other sort of compressed gas supply.  That’s where Bodner’s made common cause with freediving, and with Lady Astor’s gracious reply (" No tanks, sir!") to Mr. Churchill’s whispered proposition. In all fairness to Sir Winston, he was drunk at the time.

But Bodner’s thing is not freediving , either, since its essential feature is something most freedivers see as a fundamentally bad idea: breathing while underwater. As a freediver, I’ve not personally tried breathing underwater, so I can’t speak authoritatively to the issue. However, I’ve noticed over the years that of those friends and colleagues who gave it a try, none had anything to say about it – or about anything else, ever again.

And now, as the Monty Python crew used to say, for something completely different: Alon Bodner has come up with a way to let people do what fish do, to wit, breathe underwater by extracting the vital gasses dissolved in the water and delivering them to the circulatory system.

There’s oxygen in water, you know. As a matter of fact, ocean water is, by volume, roughly 1.5% – 2.5% dissolved air, and of the air in solution, about 34%  is oxygen.  That’s right, 34%,  not the 20%  portion of the gaseous air that’s all around us.  The reason for the difference has to do with magic numbers called  Henry’s Constants, which we’ll get to in a minute when  we examine the workings of Mr. Bodner’s invention.

But back to the more basic question , the deep philosophical dilemma. Which Deeper Blue editor is going to have to take responsibility for this kind of diving as it grows in popularity and eventually conquers the galaxy ? Is this scuba or freediving?  Who’s going to have to work harder, me or Sara-Lise ?

The underwater breathing thing – I’d argue that from a scientific point of view this stands as evidence for a variant on the scuba theme. An improvement, to be sure – possibly a revolution of the highest order of magnitude – on the method of underwater exploration pioneered during the last century by Cousteau et al

We freedivers, despite my repeated calls for comity and respect,  do tend to look down on this ubiquitous breathing fetish among our scuba brethren.  It’s not exactly a big secret that we make fun of all the clunky, awkward kit required to supply our friends with their underwater puff, and we don’t make much effort to conceal our disdain for the great noisy racket it all  makes in and out of the water.

The Bodner system, though, is decidedly less mockable. Compact, sleek, lightweight, exuding efficiency and sophistication…..hmmm, rather like your typical freediver. Even at this very early stage of the system’s development, a Bodner diver might look something like this:

Bodner Diver Sketch


Still looks a bit like a scuba diver – the bubbles are there, sure, but that thing on the diver’s back is a fraction of the size and weight of an aluminum 80. The diver in the sketch is agile, and has a hydrodynamic profile considerably less draggy than that of a conventional scuba diver.

But getting back to this breathing underwater thing – is there any way this can be reconciled with a millenia-old tradition of apnea as the proper state for a  human underwater ? Can apnea and freediving be decoupled ?

Perhaps so.

If we are candid with ourselves, we must confess that of all the ocean’s creatures, it is the ceteceans who have always excited our admiration and, if I may be brutally candid, our envy. We wish we were dolphins, and we’re becoming less and less bashful about it. Note the Borg-like conquest of freediving by the monofin over the past few years – resistance to fashion is, indeed, futile. Face it – we get in the water and we pretend to be dolphins. Adult human beings with titles like "Doctor" want to be less like Sir Isaac Newton ( more on him anon) and more like Flipper.

This is just about the dumbest question possible where fashions are concerned, but my title and seniority grant me a licence to drool, so I’ll ask it anyway: why dolphins, of all the creatures that swim in the sea ?

Well, I suppose they’re cute, but who wants to be cute? More to the point, dolphins have the big brains going for them, and I suppose we’d all love to be seen to be clever, but aren’t fish the real masters of the oceanic realm ?  Sure, ceteceans are better freedivers than we are, but they still have to come up for air.  In fact, advanced human freedivers routinely get to depths that dolphins don’t seem particularly interested in reaching. Mayol and Pellizari have both described the problems they ran into getting dolphins to dive with them down to the depths they’d set up for their photography.  So whence the dolphin–envy ?

I’ll go out on a limb here and declare that I, personally, am secure in my brainpower and feel myself free to look to fish as my aquatic role models. Yes, I’d rather have the aquatic capabilities of an ahi tuna than those of a bottlenose dolphin. I’d like not to have to come up for air.

I want to breathe water. Only then could I be a free, really free diver.

Which brings us back to Alon Bodner’s invention. Okay, so it isn’t the super-fantastic technology we saw in that epic Cameron film The Abyss – you know, the top-secret military thing where you fill your lungs with some kind of oxygenated isotonic fluid and actually, truly breathe water – but it’s definitely a step in that direction.

Alon Bodner was born in New York City in 1956 and emigrated with his family to Israel in 1964. He’s a well-schooled techie with a pair of advanced degrees from Israel’s world-class Technion (Israel Institute of Technology),  a veteran of five years’ active service (and many more as a reservist) in the Israeli Navy, and did a stint as a developer of robots. In California, where else ? All that is very respectable, but like you and like me, he’s afflicted with the aquatic bug. He loves diving. If this were a 12-step meeting, now is when we’d all say "We love you, Alon."

Bodner founded his company, Like-A-Fish, in 2001 and has already staked out a claim in the market for air supply systems that extract gasses from water. The company’s target range of applications includes individual systems for recreational and professional divers, but also larger gizmos for submarines, other types of underwater vehicle and even for permanent underwater habitats.

Nuts and bolts time. What is it, and how does it work ?

The heart of the Bodner system – the gill, rather – is an air/water separator. The trick performed by fishes’ gills, and now by Bodner’s separators is that of transforming vital gasses dissolved in the water into a form that is physiologically available to the client organism.

Bodner’s separator does this magic by exploiting Henry’s Law, which establishes that the amount of gas that can be dissolved in a liquid is proportional to the pressure on that liquid. Most of us are familiar with the demonstration of Henry’s Law put on every time we suddenly reduce the pressure on fermented barley brews – a rapid release of the carbon dioxide kept in solution under the higher pressure prevailing in the bottle before we opened the cap. 


For some reason, the tempo of research into this narrow application of Henry’s Law skyrockets during the 36-48 hours immediately following the wind-ups of freediving competitions and record events. This must be admitted as evidence that the Broder system is properly within the domain of freediving.

Passing back to gasses, ocean water has all the air we need dissolved in it under the one atmosphere of pressure at the surface.

Bodner Centrifugal I

Bodner’s problem was to figure out a way to create and contain a reduction in this pressure, thus bringing the air out of solution. His separator ingeniously utilizes a centrifuge to create a pressure gradient in the water being spun inside it.

Bodner Centrifugal II

The reduced pressure in the center, per Henry’s Law, means that the water there can  no longer hold as much air in solution as it could before being spun, and so this air is liberated– much like the carbon dioxide in your lager when you reduce the pressure on it by popping the bottlecap.   The air thus liberated from solution in the water is transferred by a small compressor into an airbag, and from there, made available to the diver.

The physics of partial pressures equilibria between the dissolved gasses, their Henry’s Constants, provides us with the most fortunate circumstance of  oxygen constituting 34% of the yield – a bonus, but one which is going to introduce oxygen toxicity as the depth limiter for this system. Check your nitrox tables – 38 meters looks like the bottom for a Bodner diver.

It seems like such a simple idea – as with so many brilliant innovations, simplicity often obscures an idea’s power.

Sir Isaac Newton ( a man whose devotion to scientific inquiry got him to push a needle past his own eyeball and into his skull in order to check out his internal anatomy) obsessed for a long time over the image of a bucket of water hung from a rope and spinning.

Isaac Newton

Newton was puzzled by something everybody else thought was too simple to think about. Sometime after the bucket starts spinning,  the water in it gradually starts to spin, too. As the water starts spinning it piles up against the bucket’s sides, leaving a depression in the center.

Sir Isaac found his way from this observation to the proposition that space is a thing, rather than the absence of things. He called it absolute space, and his doctrine wasn’t seriously challenged for 200 years until Ernst Mach ( yup, the same guy they honor when talking about jet plane speeds !) came along and knocked it down. But I digress : Newton’s conclusions about the nature of space have nothing to do with diving. But the bucket might.

I asked Alon Bodner whether the famous image of Newton and the spinning bucket had inspired his vision of a centrifugal separator device. Nobody gets through the Technion, or MIT, or Oxford without exposure ad nauseum to the Newton bucket.

“Maybe indirectly”, he conceded, a bit sheepishly. “I knew that a centrifuge would cause the mass (the water) to move outwards, thus leaving emptiness in the center. This emptiness must be of lower pressure.  Create a strong enough centrifuge and you’ll get a complete vacuum, zero pressure, in the center. But before deciding on the centrifuge solution, I toyed with the idea of controlled cavitation. Cavitation occurs often on the trailing tips of ship propellers, and is usually not desirable.”

So, this is the essence of  Alon Bodner’s Like-A-Fish underwater breathing apparatus. Not SCUBA, in my view, because the diver doesn’t bring along a ready supply of breathing gas(ses). Not Freediving as we currently define it, since No Apneists Need Apply.

Alon Bodner’s system is, apparently, in a category all by itself. It seems to be a very promising approach to a mode of diving which combines some of freediving’s minimalism, maneuverability and, well, freedom with the practicality of the long bottom times enjoyed by scuba divers.

Do not, however, rush down to your nearby dive shop with a fistful of your last unmaxed credit cards and a burning desire to become an Early Adopter.

Alon Bodner’s invention exists at this point only as a bench test model, a laboratory prototype with European patents approved and US applications pending. No one has ever dived using a Bodner system, and  Alon estimates that a fully functional prototype is about two years away. This is not, after all, the sort of thing one rushes to market without very, very careful research and extensive and incremental verification of safety, efficiency and reliability.

Bodner Lab Apparatus

Two years may seem like a long and frustrating wait for something as totally cool as a lightweight, minimalist system that will give us bottom times not limited by tank capacity, along with some of the  freediver’s agility and hydrodynamic efficiency. I asked Bodner for some insight into the R&D track he sees laying ahead of him.

“The time frame is mainly due to ergonomics and engineering.” he confirmed. “ The design of the model is almost complete. A very rough, but workable, model can be ready within one year. We need the extra time to finalize efficiency, ergonomics, and engineering problems that are likely to arise during testing.”

One totally cool engineering opportunity comes out of the centrifuge: since it takes in water and expels it under pressure, it can double as a propulsion unit ! Ideas under consideration include a back-mounted separator doubling as a jet, and, a separator housed in a scooter-like unit the diver holds out in front of him

I raised the issue of safety, pointing out that this would be a novel physiological situation in certain respects, which our existing knowledge base might not address in its entirety.

Alon agreed . “Besides creating the prototype, there are still open issues regarding safety of use. These will be dealt with in parallel with the final engineering design and construction of the model. I am in close contact with two diving physiologists who work for the Israeli Navy, and they will assist in the safety issues.”

In short, Alon Bodner is pursuing the development of his brainchild with every bit of the diligence and care warranted by what may turn out to be an historic innovation.

I wish I could get two guys from the Israeli Navy to help with safety issues here in the office. Consider the potential for bloody mayhem in the posh editorial suites high above the bustle of Fleet Street, here in the Deeper Blue Corporate Tower, seen below on the right…

London Skyline

…as the  Freediving, Scuba and Tech Diving Editors fight for control of  the Like-A-Fish story. I’ve already volunteered to test-dive with the working model.

Alon Bodner’s invention is very exciting.  I’m just old enough to remember when Aqualungs were still very exotic things, and scuba diving was something done only by wealthy daredevils, or by people with only modest concern for their own survival.

It’s too early to tell, certainly, but my gut feeling is that Like-A-Fish is the pioneer of what is going to be The Next Big Thing in the aquatics world. We’ll look at it again in a couple of years and see whether I’m  a) prophetic, or  b) off my rocker.  Come to think of it, there’s no reason I can’t be both, is there ? A synthesis of two competing approaches, much like Alon Bodner’s diving apparatus itself.

Paul Kotik
Paul Kotik
Paul Kotik has been a Staff Writer and Freediving Editor for He lives in Florida, USA with his family.