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SCUBA, Freediving, Caving, Breath Play, Poppers Administration and the Physiology relating to Kink...

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SCUBA diving, freediving, caving (cave diving), physiology and how it informs breath play, poppers usage and other kinks.



I’ve touched on this subject before in other posts but have been chastised for going off-topic. I’ve been asked by several members for more information on all of this and therefore I have decided to write this (I hope) fairly comprehensive article on the subject. I hope you find it informative and interesting...


The Author

Well I’m just a very ordinary guy who, quite unbelievably has reached 50 years old and I’ve spent over half of my life developing my extraordinary kinks. I’m very approachable and easy to chat to in person or on the phone. There’s no airs and graces with me, I tell it like it is and a spade is definitely a spade! Feel free to PM me with any observations, questions or suggestions. I’ll always endeavour to answer every contact. So don’t be shy, I don’t bite!

I’ve been a SCUBA diver for over half of my life, doing my PADI Open Water Dover and PADI Advanced Open Water Diver qualifications in 1994. Since then I’ve dived extensively in UK coastal and inland waters and overseas. I’ve been a PADI Master SCUBA Diver Instructor for over a decade and have qualifications in, and can teach, over a dozen speciality diving subjects. I’ve had experience in complex underwater lifting and transportation operations. I’m also a qualified Cave Diver and have had extensive experience in using a variety of different breathing gases other than air. I’m a qualified First Aid and First Aid for Children Instructor. However I’m not a doctor and have no medical qualifications. 

I’ve been a freediver for over 15 years and have an AIDA 4* qualification, equivalent to an assistant instructor qualification. Whilst SCUBA diving qualifications at instructor level demand a high level of academic knowledge with regard to physics, physiology, dive management and first aid procedures, it has been the training for freediving that has given me the most knowledge and understanding of, and indeed respect for, the physiological attributes of the human body. Having a kinky side to my persona as I do, this experience and knowledge has taken my kinky play to a whole new level, I consider with a much higher degree of safety than that possible without this advanced training and experience. 



I need to explain a few terms here to set a baseline of understanding of basic principles. Some members will be very familiar with some of the terms, but to be as inclusive as possible I’ve included terms here that some more new-to-the-scene folks may not be so familiar with. 


Breath play

This is a term used to describe the control of breathing gas, usually to a participant in kinky play. The breathing gas may be normal air, but could be air containing an additional substance mixed with it, such as poppers (nitrites) or laughing gas (nitrous oxide). 



Poppers is a generic name given to a range of Nitrite compounds including Amyl Nitrite, Alkyl Nitrite, Butyl Nitrite and Isopropyl Nitrite. They used to be supplied in sealed glass vials that were “popped” to release the liquid, hence the name.  Nowadays they are usually supplied in a small screw-top bottle. The effect of inhaling the vapours of poppers is to reduce *** pressure, resulting in an increased heart rate (tachycardia) and an accompanying “rush” sensation that lasts for a couple of minutes or so. The compound is used medically to ease the effects of angina. It is a powerful muscle relaxant and hence is popular to use prior to anal intercourse. It is also a powerful mood enhancer and can greatly intensify sensation and orgasm. Poppers is a liquid that is irritant and highly toxic by ingestion, do don’t spill it or get it on your skin. It is legal to use, buy and sell in the UK. It is not addictive. A small bottle usually costs less than £5 and this will last for many “doses”. Much more information is available about poppers on the internet so I won’t go into more detail here. 



This refers to the oxygen saturation level of the ***stream and body tissues. Most healthy people at rest, breathing normally will be almost 100% oxygenated. 



This is a condition where there is a lower than normal level of oxygen in the ***stream. Too little oxygen to the brain can lead to blackout and ***ness. Long duration hypoxia can adversely affect the optic nerve, creating vision disturbances.



This is a condition that occurs when cells, tissues and organs are exposed to an excess supply of oxygen or higher than normal partial pressure of oxygen. It is almost impossible for this to happen in normal conditions and it is used in hyperbaric oxygen treatment for decompression sickness (“the bends”) for divers and for treating certain other injuries. 



This is the part of the *** that carries oxygen around the body. 


Carbon Dioxide

This is a gas created by our bodies and is exhaled through our lungs. Normal ambient levels in fresh air are about 0.04%. Levels up to around 0.15% are acceptable for healthy life. Concentrations above this level (for example in a crowded office) will lead to general drowsiness and lack of productivity. At 4%, severe brain damage and even death can occur. Carbon dioxide is essential to trigger the urge to breathe and this is why prolonged hyperventilation before snorkelling or freediving is discouraged, as hypoxia can occur before levels of CO2 have risen enough to trigger the desire to breathe. 


Carbon Monoxide

This is a compound that is a product of combustion, emitted by fires, stoves and internal combustion engines in particular. When inhaled, it passes into the ***stream and bonds very readily with haemoglobin, preventing oxygen bonding with the haemoglobin, leading to hypoxia. Concentrations as little as 0.01% are considered dangerous to human health. 


Nitrous oxide

This is a gas widely used in dentistry and medicine as an analgesic and mild anaesthetic. At concentrations of up to 50%, with 50% oxygen, it is not considered toxic. It can cause euphoria and is popular for recreational use, particularly amongst young people.



Not many people realise that oxygen at high concentrations is a neurotoxin. It can cause central nervous system damage, blindness, pulmonary fibrosis and ultimately, death. Breathing air with 50% oxygen at normal atmospheric pressure is considered the safe limit, but 100% oxygen can be administered for short durations for medical reasons. Administration of 100% oxygen is recommended for any type of diving incident victim and for those suffering the effects of carbon monoxide poisoning. Hyperbaric oxygen treatment involves administering pure oxygen at an elevated pressure inside a pressurised vessel and is used to treat decompression sickness and various physical injuries. 



This is a condition where there is an excess of carbon dioxide (CO2) in the ***stream and body tissues. It is this condition that causes the urge to breathe. Free divers do hypercapnic training to develop tolerance to high CO2 levels. 



This is a condition where someone breathes at a greatly increased rate, usually without prior exertion. It has the effect of flushing out CO2 from the ***stream. Too little CO2 in the ***stream eliminates the urge to breathe, which can lead to hypoxia. Hyperventilation can be induced by breathing a CO2 rich atmosphere. 



This is a condition where someone has an increased heart rate. 



This is a condition where someone has a decreased heart rate. It can be brought about by yogic exercises or by the mammalian diving reflex.



The act of holding one’s breath. 


Mammalian diving reflex

This is a set of bodily responses to immersion that overrides the basic reflexes and is found in all air-breathing vertebrates. It optimizes respiration by preferentially distributing oxygen to the heart and brain, enabling apnea for an extended time.


Arterial Dilation

This is when arteries dilate, enabling greater *** flow.



This is when veins constrict, reducing *** flow. 


Carotid Artery

This is the artery running up the side of one’s neck, being the primary supplier of *** to the brain. Pressure on this can cause blackout or ***ness and can also cause disturbance to heartbeat and breathing rhythm. 



Viagra is a trade name for a prescription drug containing the compound Sildenafil Citrate. This is commonly used to treat erectile dysfunction in males, by combining arterial dilation with vasoconstriction to increase *** flow and pressure in the penis, resulting in firmer, longer lasting erections. It is known to increase *** flow to the vulva (and therefore sensitivity) for some women, resulting in more comfortable and more satisfying vaginal intercourse. It is also known to reduce *** pressure and therefore it is not recommended to combine this drug with poppers, as blackout and ***ness are more likely.



This is in general terms a device that atomises or mixes a liquid, gas or solid into a breathing medium to allow easy inhalation. Asthma inhalers commonly incorporate a nebuliser. 



This is a device that allows the same air to be re-breathed again and again. In diving applications or in space suits, the air is “scrubbed” of excess CO2 and additional oxygen is gradually added to maintain a constant percentage or partial pressure of oxygen in the breathing gas. A simple rebreather is achievable by breathing into a bag. More efficient systems use a pair of one way valves as well as two tubes to form a breathing loop, via a bag or “counter lung”. A short mouthpiece helps to reduce the “dead air” being repeatedly breathed in and out of the lungs, so generally the two breathing tubes (“in” and “out”) attach close to the mouthpiece. Conventional SCUBA equipment is of the “open circuit” type, where exhaled air is lost as bubbles to the surrounding water. A rebreather is usually of the “closed circuit” type, where very little air is lost as bubbles. 


Having stated the above terminology I will now explain the fundamental differences between SCUBA diving and freediving. 


SCUBA diving is the use of Self Contained Underwater Breathing Apparatus. Usually with compressed air in metal cylinders worn on the diver’s back, combined with a buoyancy compensator device and a regulator to deliver air to the diver’s mouth, the equipment allows independent underwater exploration. Depth is limited to about 50 metres when breathing air but deeper depths are possible with other gases. The diver is always breathing gas at the same pressure as the water he is in, at whatever depth he is at. So he must ascend slowly from the dive and must decompress on ascent to avoid pressure related injuries or decompression sickness.

SCUBA divers are invariably quite clumsy in the water and must move slowly and deliberately to avoid exertion. The activity can safely be carried out alone. 


Freediving is very different to SCUBA diving. There is no air supply taken on the dive, no buoyancy compensation device and the entire dive is done on the single breath taken at the surface prior to diving. A set routine of controlled breathing is followed for several minutes beforehand to reduce CO2 levels within the body, reducing the urge to breathe. Ascent from the dive can be rapid as no air has been breathed at pressure at depth. However there is the very real risk of shallow water blackout on ascent due to the reducing partial pressure of oxygen in the ***stream. This can lead to hypoxia to the brain and ***ness. Hence the reason that freediving is always carried out in a minimum group of two. In the event of a blackout there will be others present to effect a rescue, this usually only being a single “rescue breath”, administered mouth to mouth or mouth to nose. The diver’s buoyancy will decrease with depth so depending upon the weight used and the buoyancy of the clothing worn, typically the diver will be negatively buoyant below about 12 metres deep. So usually, large fins are used, or a mono fin (“mermaid’s tail”) is used to create much more thrust than SCUBA fins. Generally there is much better mobility and freedom of movement for freedivers than for SCUBA divers.


Cave diving is necessary to continue to explore caves that are flooded and have no dry passage. Oftentimes these sections are short, certainly in the UK, and long trips using standard caving equipment are necessary to reach these flooded sections of cave. 


So what has all of this got to do with fetish, BDSM and kinky play? Lots, actually. Allow me to enlarge on this here. The following section discusses how an understanding of the physiology of diving and freediving and an understanding of ropework, coupled with practical engineering and DIY abilities can massively enhance kinky play and can facilitate realisation of long held fantasies. Enjoy!

Firstly, there is the kit. Some fetishists would get a big kick from the wetsuits / dry suits alone. For others it would be the feeling of being all trussed up in some pretty tight kit. Caving gear is something else however. The harnesses and rope work used can be put to very good use in bondage situations. Having the ability to tie appropriate knots and to be able to suspend or secure someone properly with harnesses and ropes or straps is a really kinky thing in and of itself. Add to this the various pulleys, rope jammers and anchor points used and you have some pretty useful extreme bondage kit, if you know how to use it.

Secondly, it’s the whole breathing through a regulator gag thing that’s also very kinky for some. 

But the real benefit to me has been the massive amount I’ve learned about my own physiology, about how my body works, what it can do and how to get the absolute maximum pleasure from kinky play. I’ve translated this into my play sessions with others, because I have often understood their body so much better than they have. It all comes from applied knowledge and experience, naturally.

My big kinks are large object insertion and fisting. If I can be securely bound and restrained whilst this is being done to me, so much the better. So clearly, for large object insertion and fisting to take place safely, there needs to be loads of lube, but the most important thing is relaxation. If you’re tense it’s never going to happen. The sphincter muscles need to relax fully and certainly poppers can help this somewhat. I’ll come back to this shortly. 

Freediving is all about relaxation. You get yourself into a really relaxed state before the dive and your heart slows to about half of its normal rate, due to the mammalian diving reflex. There’s quite a lot of yoga techniques used and it is without a doubt the most relaxing of activities. So applying some of these techniques before and during my play sessions has helped massively to get me “in the zone”. I can feel my body adapt and it almost subconsciously gets itself ready for what’s to come. That’s an amazing feeling, almost as if you have another being inside you, running around tidying up the loose ends and getting your body ready for the big event! This is very much along the lines of what happens when you do a deep free dive: the spleen actually contracts during, or even slightly before, the dive, to squirt a whole load more haemoglobin into the ***stream to carry the oxygen around the body. Absolutely amazing, really, that the body can do something like that involuntarily and subconsciously. 

So certainly the freediving experience I’ve had has helped enhance my play enormously. In a breath play scenario, the knowledge that you are not going to simply “conk out” just because you can’t breathe for a few seconds, even if it is uncomfortable, leads to a deep state of relaxation because you know that you’ll be just fine. The discomfort is caused by the CO2 levels indicating to your brain that you need to breathe, but you’re not going to die because of lack of oxygen!

A word or two here about the Carotid Artery. There are two of these, either side of the windpipe or trachea. These supply *** to the brain, face and neck. Part of these arteries contain sensors that help to regulate *** pressure. Pressure applied to these can cause blackout and ***ness. In trained hands, someone can be rendered *** within a couple of seconds. It’s worth remembering this during kinky play: never restrict the neck with tightened straps or ropes. It’s very dangerous and can cause death within a couple of minutes. 

Another massive enhancement in the pleasure I’ve gained from kinky play sessions has been my development of suitable methods of administration of poppers. Everybody I’ve ever seen take poppers over the last 25 years, absolutely without exception, have simply sniffed directly from the bottle, usually blocking one nostril with a finger or thumb and inhaling in the other one. Many people I’ve seen also have sore, red patches around their nostrils due to tissue necrosis caused by the irritant poppers liquid coming into contact with the skin. This is because poppers will grab whatever oxygen it can get, so it grabs oxygen from your skin, effectively burning it. Really not good! So I’ve always used a short length of plastic tube with one end in my nostril and the other in the neck of the poppers bottle. A John Guest Speedfit 15mm pipe insert from your local plumber’s merchant is perfect, as there’s an O ring that’s really comfy in your nostril. You need to be careful that the pipe doesn’t dip into the liquid, especially if the bottle is new and fairly full; you really don’t want to inhale the liquid straight into your nasal cavity. That would be very dangerous. Done correctly though, the air is dragged into the neck of the bottle and this has the effect of nebulising a lot of poppers vapour into the air that is breathed up the pipe, resulting in a powerful hit. It works best in a larger bottle that’s half empty. 

But all of this relies on my hands being free and I can’t do this when restrained. Having a play partner administer it this way for me isn’t such a good idea either, especially if they are also using poppers and may have impaired judgement. So I developed a really excellent rebreather system that allows me to be fully restrained or bound and my play partner to be able to very easily administer poppers to me as and when they choose. Of course, the power dynamics of bondage and submission further enhance this scenario. The system has all been designed and made to be assembled and disassembled in seconds, with instant disconnection if required, to allow immediate normal breathing in a safe word situation. A breathing bag can be used to create a hypercapnic state, with the facility to introduce a poppers-soaked tissue or rag into the breathing loop when required. The effect of this setup is phenomenal compared to the aforementioned “sniffing from the bottle” method. 

There are a few simple knots that are worth learning to facilitate successful and easy bondage and restraint without having a degree in shibari. These are knots frequently used in caving. There’s nothing worse than massive delays due to incompetent rope tying! What a turn-off...

Basic joinery and engineering skills are in my opinion a huge enhancement to bondage and restraint scenarios. Having the ability to properly use a cordless drill/driver to secure a cleat or pulley to a plywood restraint board without hesitation is a great facilitator to a fun session. In the workshop, having the abilities to weld, saw and grind metal and to shape, cut and fasten wood enables a kinkster to create all of the equipment needed to live out their fantasies, all for very little cost. 

All of the aforementioned breath play and control equipment was made out of readily available off the shelf items from a plumbers merchant, all for just a few pounds. I have made thrusting machines using only a few nuts and bolts, bits of scrap steel and a few lengths of wood, assembled with an old windscreen wiper motor or old cordless or mains powered drills, again, for just a few pounds. The best and most fun insertable toys I’ve ever used have been made with foam pipe lagging, duct tape and 38mm waste pipe, all put together in just a few minutes! I’ve also made gags from foam rubber and duct tape, secured in the mouth with common kitchen cling film. There are a plethora of other items that can be used as toys. Cord and rope is cheaply available at B&Q, as is pipe lagging.

There are pipe bungs used for pressure testing waste pipes that make the very best inflatable toys that are a million times more durable and satisfying than the regular commercially available inflatable toys you can buy online. Oh, thank goodness for plumbers merchants!

So when wanting to push the boundaries into new and uncharted territory, perhaps the attributes a really adventurous kinkster needs to look for in a potential play partner are not so much “are they hot?” or “have they got a nice body?”, but should be more along the lines of “do they dive or do caving?” or “have they got a well fitted-out workshop?” or “can they tie knots proficiently?” and most importantly “are they any good at DIY and engineering?” Any of these skills, when coupled with a generally kinky bent will greatly enhance the potential for a fantastic time to be enjoyed by all!

Finally, if any of this piques your curiosity and you need to discuss anything further, or if you just have questions that need answers, I’d be very happy to have a chat over the phone if you PM me via this site. Happy kinking...


Wow you are looking handsome if you want to chat with I am there for you I am looking for a serious relationship

Flo, what an absolutely irresistible offer; thank you so much. Now you might like to read my profile. The fact that you are in Tampa, Florida and I am on the west coast of Scotland has clearly escaped your attention. Your post might have been better suited to a private message to me, rather than posting it on a forum post about SCUBA and Freediving… but thank you anyway!

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