KIS: Part Two

By Jean-Marc Claes


If you did not read KIS: Part 1, please return to our magazine, edition December 2023 (download it for free on and read it first. It will help you to follow this KIS: part 2.


The KIS principle is this: Keep It Simple. The idea is to simplify procedures, tools, equipment, and training to increase safety!


In scuba diving, we should never forget that we are taking people in a different environment; taking them below the surface means changing them from gas into liquid. A new surrounding that is not our “used” location but rather a more dangerous, challenging location.


On planet Earth, we can be in the air, on the ground or below the surface. All those environments have their challenges, but we are more acquainted with the feet on the ground than flying in the sky or diving below the surface. In these two rather different circumstances, we are equipment-dependent, or your experience will be rather very limited or short or have a catastrophic ending, for sure not a happy ending.


In the development of staying prolonged in these rather hostile environments, using specific equipment will make our stay longer, safer, and more relaxing.


The first step in developing the needed equipment is translating the challenges into technical possibilities. The next step is to design tools based on these technical possibilities.


Scuba diving was ‘invented’ in several stages during a period spanning a few hundred years. We have made some steps from the hard helmet divers to the current full technical CCR (*) divers. SCUBA, the word itself, is an abbreviation: Self-Contained Underwater Breathing Apparatus.


Many people have forgotten that at some point in the development of the scuba diving industry, we needed to ‘cut’ the umbilical cord or connection between the hard hat helmet diver and the pump system at the surface in order to create “freedom” and have the scuba diver swim around freely, not depending on a surface connection. This was done with the invention of the scuba regulator to create breathing comfort and the pressure-holding dive tank to create time spent underwater. Then, the scuba diver was born…


Credit for this goes mainly to the French Commander Jacques Cousteau, who oversaw the team that developed most of the equipment, making these steps possible. He also brought scuba into the public, making it all visible as television developed around the same time; he became the leading ‘known’ expert. Credits should also go to other developers and engineers who did not make it to public fame like Cousteau. Names like Emile Gagnan should be mentioned here.


But where does this lead us regarding KIS? Cousteau made fame and fortune around the 1950s forward; his company Aqualung is still one of the leading scuba equipment manufacturers in the world. We can state that about 75 years of evolution in scuba diving have brought many developments and innovations by Aqualung and many other companies.


But did they all use the KIS principle? Did they all make scuba diving a safer activity?


Now, the idea here is NOT to start discussing all the wrong ideas, designs, and productions of scuba gear, although it could be an interesting study!


I remember visiting the DEMA show in Las Vegas some years ago and looking/fitting on the first ‘rebreather’ helmet and thinking, this is not KIS. Not long after that, the designer was killed using/testing his product; it did not surprise me.


No, that list would be too long and too negative. I want to look at the current equipment, users, procedures, and decisions we take/make while diving and see how KIS we are!


I want to put the following piece of equipment in the spotlight: the octopus, part of the alternative air source options (**).


There are plenty of alternative air source options for a scuba diver to choose from! Somewhere along the 1980-1985 timeframe, the scuba diving industry came up with the idea to introduce the use of alternative air source options while scuba diving to increase safety.


So, what was used before this date?


A look into scuba diving history shows you that we were using dive tanks with an integrated safety on the scuba tank valve: A spring release system was used to close the air supply off when reaching ‘around’ 50 bar (depending on the type of spring and the wear/corrosion of it), and so the scuba diver was warned that his air supply was getting ‘low.’ The next step would be releasing the remaining air supply by pulling a long lever mounted on the side of the scuba tank to move the spring into an unlocking position, releasing the last bit of air.


Looking at it from a KISS principle, this mechanism had some real disadvantages. Don’t forget, the pressure gauge was not ‘in use’ yet at that time! The disadvantages mostly come down to the fact that users forgot to activate the spring before the dive, therefore creating a complete ‘out of air’ situation during the dive as they would ‘think’ still having some air left after being ‘out of the air’ believing the spring activation would release another 30-50bar while in reality, the tank was completely empty as the spring was not put in place before the dive! Believe me, that created some nasty surprises with many divers in the 60s-80s.


A second more ‘cumbersome’ problem in this situation was using the one-staged or double hose regulator, as we call it, in some parts of the world. For those scuba divers reading this here who have never tried this type of regulator, well, TRY IT! These days, you will still find the old/odd models available through dive shops and dive specialists in perfect working condition, ready for another ‘back into history’ dive. As a matter of fact, I even own a few of these models in perfect working condition, so if you ever come around, don’t hesitate to ask me.


Back to the out-of-air situation. The scuba divers needed to share the double hose regulator, and the only way to do this was to be positioned ‘on top’ of each other, being able to pass the double hose mouthpiece from one diver to the next. That’s quite an interesting emergency position you have there, with limited communication possibilities between the divers. Don’t forget they still needed to get to the surface! The amount of training that was needed to ‘master’ this technique, imagine?


When the two-stage regulator was introduced, the options of sharing air were expanded, and the use of an optional second stage or Octopus was available! Soon after that, many dive training organizations started to talk about having an alternative air source as recommended and, after that, “required.” These days, we do not even think about it anymore. However, there are still several other options besides the octopus: Spare Air, pony bottle, and integrated air source/inflator—a complete array of options, primarily different by price.


Is that where we choose what to use? Or do we choose the safest option? And what choice would that be? And when selecting that option, do we really use it as prescribed? Take the time to analyze this for yourself.


(*) CCR: Closed Circuit Rebreathers: diving using a technical device that circulates the breathing gas from the diver, filtering it from the CO2 produced and adding oxygen instead.


(**) In the earlier December magazine, we discussed another part of the dive equipment, being a subpart of the regulator…see (December 2023 edition)

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