潜水窒息的风险

Apnea diving hazards

Warning: Mind apnea dangers!

home_fr.htm../../apnee.htm
apnee.htm

Translated by Benjamin ROTTIER

Apnea diving is an age-old activity. In wrecks of galleys, that were containing amphoras of wine or olive oil, discovered near the coasts of the South of France, where the sea is twenty-five meters deep, big stones were found that couldn't have rolled down from a cliff. Each was 11 to 22 lbs in weight, and looked like a big pebble. For a long time, the presence of those stones has been a headache for archaeologists, until they realized that put into rope baskets made of vegetable fibres, they were used as a weight for divers to go down into the hold of sunk ships to try to do raising operations.

At that time the ship-owner, when it was possible, already attempted to raise his valuable cargo, when the sea was not so deep. In those days, human lives were not worth much.

Apnea, in a dictionary, is defined as a voluntary stop of breathing. But what happens when you hold up your respiration? Very soon, after a few dozens of seconds, you'll feel a painful sensation of asphyxiation, that becomes quickly unbearable and forces you to breathe again. The cause of this feeling is the increase of the level of carbon dioxide in your blood (or, more precisely, of the partial pressure of carbon dioxide; the difference will be explained below).

What can you do to increase the time of apnea? There are three ways to go about it:

• the first one consists in controlling this asphyxiation feeling. That's what some divers do, using techniques ressembling Yoga (the same that would allow e.g. to control a pain);
• the second one consists in putting the maximum volume of air into your lungs before you stop breathing, e.g. for diving;
• the last one consists in doing a hyper-ventilation before a dive.

To increase the time of an apnea dive, the third way is by far the most efficient; but it's the most hazardous too. Let us see why! For hyper-ventilating himself, the diver will be gasping for a more or less long time. Doing this, he does not necessarily take a powerful inspiration, but he is ventilating his lungs efficiently: he evacuates the residual air and replaces it with some fresh air. It's known that when you're breathing normally, all the air contained in your lungs will not be replaced at each exhalation-inspiration. This mechanism is controlled by muscles: the diaphragm, and to a lesser extent the muscles that put down and lift the ribs. But the technique has its limits. Doing this, you won't be able to empty your lungs totally. When you're ventilating the pulmonary volume by panting, you replace nearly all of the air. So the lungs will contain a fluid that is identical to the surrounding air, and no more to the combination of the inhaled air and the residual air, loaded with carbon dioxide, as a result of the previous respirations.

To put it clearly: hyper-ventilation reduces the amount of CO2 contained in the pulmonary air. The haemoglobin is a blood molecule able to catch and to carry both the oxygen (oxy-haemoglobin) and the carbon dioxide. The hyperventilation reduces thus not only the amount of CO2 in the lungs, but also its amount in the blood.

You can't increase the percentage of oxygen contained in the atmospheric air (20 %, the rest being nitrogen), but you can increase its amount in the blood. If you continue the hyper-ventilation after a few dozens of seconds, you'll feel dizzy; this phenomenon is the expression of the blood's enrichment in oxygen. If you hold up your breathing, on the surface or one meter deep, in a swimming pool, staying perfectly motionless, you'll be surprised by the raise of the result in apnea. Apnea times of one minute can so be get quite quickly. With a training, many a man can reach one minute, still without the least effort. The human maximum is about 4 minutes, for the 'record-holders of speciality'.

Why are you able to hold out such a long time without breathing?

It's not so much because you've loaded the blood with oxygen as because you've impoverished it in carbon dioxide, before the apnea. But the CO2 is precisely a danger alarm. The hazard is the fainting fit that will happen when the oxygen level in the blood gets under a threshold. It's extremely dangerous, as there's no warning sign such as an uneasiness feeling. That's instantaneous and makes the diver lose consciousness, without any resumption of the breathing activity. Someone who is drowned this way will keep his lungs dry. That's how apnea works after a hyper-ventilation. A diver using this technique will increase his results significantly, but on the other hand he will switch off his warning device (the asphyxiation feeling due to the raise of CO2 level in his blood). He may faint without having felt the least suffocating feeling.

Apnea is mainly used for free dives. In those conditions, the diver will ask himself:
- As I wish to get to a given depth, should I swim powerfully to reach this depth as fast as possible during the apnea given time, or on the contrary should I minimize my efforts, both during the descent, in depth and during the climb up?

The second way is the right one. An apneist shall swim, dive, glide being economical in his movements: no sudden movements, no intense muscular effort are allowed (they're correlative to an increase of the consumption of oxygen). The diver, carefully weighed down, shall descent and climb up slowly, with no haste. The use of a wetsuit is essential, unless you're diving in very warm water. The fight against the cold is indeed accompanied by a strong raise of the consumption of oxygen.

Any useless effort shall be avoided, as any useless consumption. As part of it, the intellectual activity, the simple functionning of the encephalon, make consume a lot of oxygen. This is far from being negligible. If you carry out apnea experiments, you'll be surprised to notice a significant reduction of your results if you're making complicated calculations. Thus, consciously or unconsciously, the apneist get used to being non-thinking when he's diving. If he succeeds in not thinking about anything, his performance shall be better. Doing this, he is using the rudiments of meditation techniques (Buddhist, Hinduist, Yogi) without knowing it.

The masters who encourage their disciples to meditate start telling them: 'suppress the flow of your thoughts'. What happens then? I don't have any ability for telling you. Either the meditation drops human beings in contact with any transcendant mental activity, changes their state of consciousness, or the brains might send oxygen towards centers usually less fed with it (the centers of conscious thought, when in normal conscious state, catch it first). The result is a feeling of well-being, that any apnea diver has. An efficient apnea is synonymous with well-being, or else it is not efficient, quite simply because it can be done only in a non-thinking state.

Before achieving spiritual enlightment, or nirvana, thanks to non-thinking, the apneist likes to have to behave this way spontaneously, which can do you good when one is stressed or obsessed. Of course, apnea diving lets you in addition appreciate the beauty of underwater landscapes. But the mystical dimensions it has for a good many divers is based on an objective reality, only few are aware of.

From the point of view of the capacity of the physical machine, divers may reach a depth of 30 meters, doing an apnea of one minute and a half or two minutes. Some 'particularly gifted' persons can even do more. This activity is like Russian roulette. Those 'supermen' only reduce ill-consideredly the gap that separates them from a fatal fainting fit.

So, what can you do? Decree once and for all that apnea diving is a highly dangerous activity, or try to find a compromise?

Before venturing with figures, one should be informed. Fatigue, e.g., considerably increases the hazard: it may also be overwork, the lack of sleep, any cause of tiredness.

When I was around 20, I was used to doing apnea dives, during the holidays. In winter, I sometimes went into a 50-meter-long swimming pool (The Tourelles' swimming pool, in Paris). I was quite fit and so I was able to swim across the pool one meter deep, with flippers (that was equivalent to dive to a depth of 20 meters and to come back to the surface). Apnea at such a small depth may look safe. Serious mistake! At that time, I was fully preparing for the entrance examinations for Grandes Écoles. I slept very little and I was working a lot. I thought that going swimming would do me good. I started diving in the deserted pool. I had done that a lot of times, but only as I was fit; that day, I was a bit tired. By chance, I was swimming towards the shallow end. I never reached the edge of the pool. At about 40 meters, I had a fainting fit, instantly, with no heralding sign. I have no memory of the event. I guess someone found me, lifeless, floating in the water, and raised the alarm. I regained consciousness on the edge of the swimming pool, having been resusciated by the lifeguard.

Just imagine what would have happened if I had swam into the opposite direction. The Tourelles' pool has a ten meters high springboard; it overhangs the deep end, that is 5 meters deep. If I had dived towards the deep end, I might have gone deeper with the run and fainted at that time. The buoyancy of a human body depends on the depth it is. Even with the lungs filled with air, the pressure compresses them, and this reduces the Archimedes' pressure in a equivalent measurement.

As I had a fainting fit one meter deep, I came back on the surface naturally, keeping the air in my lungs even if I lost a little on the way. Under a few meters of water, I would have gone straight down; I would not have been so easy to spot anymore, and when someone would had seen me at the bottom of the pool, it would have been too late.

As soon as the faint occurs, the encephalon cells are no longer fed with oxygen. The problem is that their autonomy is not so big. If drowned persons have sometimes been saved after a significant immersion time, in icy water, it's still exceptional. We may consider that someone who has had no oxygen at all for about 5 to 10 minutes is quite simply dead, for good.

You may have noticed that when rescuers give mouth-to-mouth resusciatation to a drowned person, they're ventilating his lungs not with atmospheric air but with the air they're exhaling. They so hope that it will lead more quickly to a resumption of the respiratory reflex, that is controled by the carbon dioxide level.

Why do we have a 'tendency' to breathe? Quite simply because with time the CO2 level in the blood increases, and when it goes past a threshold the medulla oblongata, that recieves the information, sets off straight away the inhalation movement. Otherwise, people should consciously decide to breathe, or either they would faint.

Any tiredness increases, as we've seen it above, the dangers linked to apnea, that are always present. That is the same for the cold. In a colder water, the heart rate will raise, as does the cells' metabolism. For it to play his role of pump, the heart also consumes some precious oxygen. In cold water, even with a wetsuit, the results shall be revised downwards. The extremely serious problem of apnea is that nobody can know at given time and set-up where the deadline is. The question 'how long can I have an apnea before I faint today, having my physical condition, in that water?' can not be answered unless... you experience it. It's highly probable that a great many of times people have been at a fraction of second to death, without even noticing it.

During the dive, each sudden effort goes with an overconsumption of oxygen likely to make its level go under the fateful threshold. That's how my friend Josso died, 40 years ago in Corsica. We had been students together in the École Supérieure de l'Aéronautique in Paris in 1960. Josso was used to diving with the Roubaix family. Mrs de Roubaix had been the women's champion of harpooning. They all had a passion for harpoon fishing and the sea near Corsica was rich as it no longer is. Josso was diving reasonably. That's at least what he was thinking. But one day, as he was a dozen meters down, he shot a grouper that settled on a stone. Josso slided into the crevice and made efforts to pull the fish out from its refuge. The consumption of oxygen it needed caused a fatal faint.

A well-trained diver can reach a depth of 15 or 20 meters if there is nearby someone else who doesn't take his eyes off him and who is likely to help him immediately (not to constitute a second would-be drowned person). Harpooning championships can't be done at a depth of 10 meters. Water well-stocked with fish, above all in our areas, matches with more significant depths. Competitors usually dive in tandem. Each member of the crew dives in turn, being watched on by the other. But the solo apnea dive at a great depth is nothing else than Russian roulette.

We have mentioned above the oxygen partial pressure. In fact, the transfer rate of oxygen into blood depends on the relative density of molecules close by blood cells. The more significant the density is, the more intense the transfer is; that's quite logical. Thus, when professional divers go down very deep (more than 100 meters), what they use for breathing is a mixing where the percentage of oxygen is set well lower than the usual 20%, otherwise the oxygen would become too much oxidizing. From the start of the dives with breathing equipment, people who wanted to dive with pure oxygen in their bottles had convulsions. When its concentration is too high, oxygen is like a toxin.

When a diver goes in apnea 20 meters deep, he is under a pressure three times higher than the atmospheric pressure. The blood thus may be still fed with oxygen although it is scarcer in the air contained in the lungs. The influx of oxygen remains stable with a poorer air because the pressure is three times higher and so the density of oxygen molecules is three times higher too.

The situation is reversed when the diver climbs up. The human body reacts not only to the decrease of the oxygen level in the blood but also to the fall of the influx of oxygen. In fact, when the diver climbs up, he goes from a pressure three or four times higher than the atmospheric pressure to a pressure near to one atmosphere just under the surface. The blood rush then falls down. That's why a great many of fatal fainting fits occur when the diver is climbing up. Some specialists even speak about the '9 meters fainting appointement'.

Thus, when he is in depth and even if the oxygen he has in his lungs won't allow him to come back alive to the surface, the diver feels very good. If he only thinks he is a superman, he won't make the decision to climb up early enough and he will pay with his life for his carelessness.

From a depth of a few meters, the compression of air (contained in the lungs or in the alveoli of the wetsuit) gives him a negative buoyancy. He who faints climbing up won't reach the surface but will sink straight down.

Let us be clear. If you should remember something about this article: Great depth apnea is not a sport but a bloody stupid thing. Apnea has not made any progess. The human machine is still the same. Simply instead of staying far enough from the disaster, e.g. one minute to it, people come up to it in a foolhardy and morbid way. The followers of long time apneas or of solo and great depth apneas are quite simply people who flirt with death, as they're resurfacing a few seconds before the fatal fainting fit, knowing it or not.

At the best, you'll just be warned and you'll get off lightly. At the very worst, it will be irremediable.

About 15 years ago, a general craze for free dive at great depth was born. Two men are directly responsible for this phenomenon. The first of them is the diver Jacques Mayol, the second the film maker Luc Besson.

As soon as apnea dive developped, just after World War II, people wanted to know 'how far we could go'. Some 'supermen' went into a race for the result, notably the Goliath Enzo Majorca was. It's sure that nobody is equal before the apnea dive. The limits for a man won't necessarily be the same for another. But whatever the case, the limits exist and several champions lost theirs lives for having reached theirs. In the field of high-risk sports, and apnea is one, nothing is obviously more dangerous than to think oneself upper than other human beings. That's valid for many other activities as well, like bare hands ascent, without any belaying, etc.

Mayol moved towards a different kind of performance. Instead of going down to increasing depths by his own means, he was pulled down by a heavy pig fixed to a mobile part running along a cable.

He climbed up with the aid of a blown up balloon, always to avoid any physical effort and its overconsumption of oxygen. Thanks to this technique, Mayol was the first to exceed a depth of 100 meters in 'free dive'. For he to do his feats, there was a string divers equipped with bottles spaced out all along the descent. If a fainting fit had occured, one of those who were keeping a watchful eye on him would have immediately taken him back quickly to the surface. He will probably die in his bed.

Interest of this kind of activities: not so great. The air contained in the lungs is compressed when someone dives. At a depth of 10 meters, his thoracic volume is reduced twice (Mariotte's law: the pressure is doubled, because 10 meters of water are equivalent to one atmosphere). At a depth of 100 meters, the volume of the pulmonary air is divided by ten. At that time, some feared the ribs could be broken. It has not at all been the case. The diaphragm simply went up into the ribcage. It was known too that the respiratory rate decreased during a dive. A control done on Mayol showed that the reduction was tangible and very quick, as if the human body was adapting to new conditions.

It was above all to attract media attention. Those feats were more spectacular than anything else. Today, nobody is interested in these records any longer and no one remembers the name of the record-holder of the speciality, that is closer to a circus act than to a sport. For many years, Mayol has been using a cheat without anyone knowing it to achieve his feats for long time apneas (three or four minutes). Before each new 'feat', he was going in the Andes, to Lake Titicaca where he was having some dives, at altitude. As the air is there quite poor in oxygen, the blood changes quickly and get enriched in haemoglobin (the composition of the blood changes in a few days). If Mayol was attempting his exploit in the days following his return, his apnea ability was artificially increased, compared with those who did not know this trick. It's known today that the East Germans have won several sport competitions by training athletes in totally closed stadiums, kept in depression. To secure the results, the blood of the athletes was getting enriched. Outdoors, they could then glean medals thanks to this 'natural doping'.

Mayol's results were coming only after a show of meditation. He claimed that he had followed an initiation by a zen monk. Getting out of the water, our 'monk-diver' even let out a 'primal scream', etc. to the cameramen's great delight.

The film maker Luc Besson decided to show the life of Jacques Mayol on the screen. He was a diver himself and had known the 'dolphin-man' for a while. The result is a cult-film: The Big Blue has been a worldwide success.

Undeniably, Besson is a very good film maker who knows how to chose the shots, the lighting, the actors. The film relates the story of a man apnea fascinates (Mayol accepted the character to use his name, in this romanticized story of his life). The film is punctuated with competitions and feats. A woman tries desperately to divert the 'hero' from his run towards the abyssal plains that seem absurd to her. In the last scene of the film, she says to 'Jacques Mayol' she's pregnant with him but that's not enough to divert him from his obsession. We see him diving for the last time towards water so deep that darkness prevails. Some dolphins come joining him and the 'dolphin-man' sinks in the darkness, far away from the spotlights.

Homo Delphinus was moreover the title of a book published a few years earlier by Jacques Mayol. He was convinced that man comes from a 'swimming monkey' and he did not miss any opportunity to hold up his theory. The fascination caused by this film and those absurd ideas claimed five hundred casualties all around the world, in particular among young people. A journal called **Apnea was created in France, where the rudiments of the 'extreme dive' were explained. Among the victims of this disaster: my son Jean-Christophe who drowned off Marseille in the summer of 1990. He was twenty-three.

I had taught him to dive from his teen-age and we had done harpooning (and so apnea) in many seas around the world, in particular in the Caribbean Sea and in the Red Sea. But fortified by my own experience, related above, I had warned him from the start about the strict limits of this activity. In spite of a good predisposition, we had never dived deeper than about 12 meters and longer than 30 seconds. We were therefore well below our real abilities. Without my knowing,

The Big Blue

film (I've learned after he had watched it five times) was to appeal fatally to my son. Following some 'technical advice' given by

Apnea

, the journal we found in the boat that had brought him upright the wreck of

Saint Dominique

, 30 meters deep, he had quickly increased the depth and the length of his apnea dives, without filling me in about this drift. The circumstances of his decease reveal the impact of those absurd ideas on the world of divers.

My son had met Pierre Vogel, a shopkeeper, who owned a shop called 'The Old Diver'. Vogel, now dead, had been one of the pioneers for the dive in this area. One day in July, 1990 he took my son with him on his boat to make a dive to see the 30-meter-long wreck of a sailboat named 'Saint Dominique', not far from Marseilles. Vogel, about 60, was still diving with breathing equipment. There were five persons on the boat that day: my son, Doctor Saint Jean (a doctor well informed about the problems linked to the dive), Professor Ebersoldt (a kind of german Jacques-Yves Cousteau, author of many books about diving) and a Brazilian named Barrillo; all three were seasoned divers. Ebersoldt came with his teen son who did not dive that day. The four divers, equipped with wetsuits and bottles, dived towards the bridge of the Saint Dominique after they had casted the boat's anchor. While they were going round the wreck, my son started playing cartesian devil diving 30 meters deep in apnea and joining with them. Ebersoldt then took a first photo of him near the stern castle of the wreck. None of them got worried about the behaviour of my son. After the accident, Pierre Vogel made those comments (I had asked him the permission to record our discussion):

- Apnea has made a lot of progress [...]. That has nothing more to do with what you knew. There are today a great many divers harpooning or diving at such depths. We keep a watchful eye on the customers, but we let friends to what they mind [...].

Seeing a young diver doing apneas 30 meters deep near them did not worry those three men, aged from fifty to sixty. They just dived further taking no longer any care of him. After the dive, they climbed up doing their decompression stages. That's only after they had taken all their equipments off that Vogel first questioned Ebersoldt's son on 'the diver'.

• No, I haven't seen him for quite a while, answered the teenager (the boat was several miles away from the coast).

In a complete panic, the three men re-equipped themselves trying moreover to place the boat above the wreck, thanks to seamarks (markers taken on the coast). Meanwhile, they had weighed the anchor and the boat had moved. When they fetched the body of my son, it was too late in spite of the efforts displayed by Doctor Saint Jean.

Although I've been successively in contact with the four divers, I've never had a coherent version of the accident. Vogel, who first seemed to be very sure of himself, started hiding the presence of the fourth diver (the Brazilian) from me (There were three of us: Saint Jean, Ebersoldt and me...). The German, I talked to on the phone, hedged when I asked him in which conditions he took a photo of my dead son lying on the wreck's deck, a snapshot Vogel had sent to me by mail. I knew the existence of this fourth diver by doctor Saint Jean. When I had another contact with Vogel, he became flustered (Oh yeah, I remember now, there were four of us...). Of course, my son has not been the victim of criminal intentions, but it seemed clear to me that those four were not very proud of what happened that day.

You can't rewrite the past or bring people round. But at that time, four experienced divers, who were not tenderfeet in diving, one of them being a doctor, came to consider solo, great depth apnea dives to be an unremarkable event, calling no reaction.

闭气潜水的危险

警告：注意闭气的危险！

home_fr.htm../../apnee.htm
apnee.htm

由本杰明·罗蒂埃翻译

闭气潜水是一种古老的活动。在法国南部海岸附近，海水深25米的沉船中，发现了装有葡萄酒或橄榄油的陶罐。这些沉船中发现了一些大石头，它们不可能从悬崖滚落下来。每块石头重达11到22磅，看起来像一块大鹅卵石。长期以来，考古学家对这些石头的存在感到困扰，直到他们意识到这些石头被装在用植物纤维制成的绳篮中，被用作潜水员的配重，以便他们下潜到沉船的货舱中尝试打捞作业。

在那个时代，当海水不那么深时，船主会尝试打捞他的贵重货物。那时，人类的生命并不值钱。

词典中，闭气被定义为有意识地停止呼吸。但当你屏住呼吸时会发生什么？很快，在几十秒后，你会感到一种痛苦的窒息感，很快变得难以忍受，迫使你重新呼吸。这种感觉的原因是血液中二氧化碳水平的增加（更准确地说，是二氧化碳的分压；下面将解释这一差异）。

你可以做些什么来延长闭气时间？有三种方法：

• 第一种方法是控制这种窒息感。一些潜水员使用类似于瑜伽的技术（例如，控制疼痛）；
• 第二种方法是在停止呼吸前将尽可能多的空气充入肺部，例如在潜水时；
• 第三种方法是在潜水前进行过度换气。

要延长闭气潜水时间，第三种方法是最有效的；但也是最危险的。让我们看看为什么！为了过度换气，潜水员会喘气一段时间。这样做时，他不一定进行强烈的吸气，但会有效地通风肺部：他排出了残余空气并替换成新鲜空气。众所周知，当你正常呼吸时，肺部中的空气不会在每次呼气-吸气中被完全替换。这种机制由肌肉控制：膈肌，以及在较小程度上由上下肋骨的肌肉。但这种方法有其局限性。这样做，你无法完全排空肺部。当你通过急促呼吸来通风肺部时，几乎会替换掉所有的空气。因此，肺部将包含与周围空气相同的液体，而不是之前呼吸所残留的空气和二氧化碳含量高的空气。

简单地说：过度换气减少了肺部空气中的二氧化碳含量。血红蛋白是一种能够捕捉和携带氧气（氧合血红蛋白）和二氧化碳的血液分子。因此，过度换气不仅减少了肺部中的二氧化碳含量，也减少了血液中的二氧化碳含量。

你无法增加大气中氧气的百分比（20%，其余为氮气），但你可以增加血液中的氧气含量。如果你继续过度换气几十秒后，你会感到头晕；这种现象是血液中氧气丰富的表现。如果你在水面或一米深的游泳池中保持完全静止，你会惊讶于闭气时间的显著提升。因此，闭气时间可以很快达到一分钟。经过训练，许多人可以达到一分钟，而且几乎不需要任何努力。人类的极限大约是四分钟，对于“特殊项目”的纪录保持者而言。

你为什么能长时间不呼吸？

这不仅仅是因为你将血液中的氧气加载，而是因为在闭气前你已经减少了血液中的二氧化碳。但二氧化碳正是危险的警报。当血液中的氧气水平低于临界值时，会发生昏厥。这非常危险，因为没有像不适感这样的预警信号。这是瞬间发生的，使潜水员失去意识，而没有恢复呼吸活动。这样溺水的人会保持肺部干燥。这就是过度换气后闭气的工作方式。使用这种技术的潜水员会显著提高他的成绩，但另一方面，他会关闭他的警报装置（由于血液中二氧化碳水平上升引起的窒息感）。他可能在没有任何窒息感的情况下昏倒。

闭气主要用于自由潜水。在这种情况下，潜水员会问自己：
- 我想达到某个深度，应该在闭气时间内尽可能快速地游泳到该深度，还是相反，应该在下潜、深度和上升过程中尽量减少努力？

第二种方法是正确的。闭气潜水员应该游泳、下潜、滑行，动作要经济：不允许突然的动作或强烈的肌肉努力（它们会增加氧气的消耗）。潜水员应谨慎配重，缓慢地下潜和上升，不要匆忙。除非在非常温暖的水中，否则使用潜水服是必不可少的。对抗寒冷确实伴随着氧气消耗的显著增加。

任何不必要的努力都应该避免，任何不必要的消耗也是如此。其中，智力活动，大脑的简单功能，会消耗大量氧气。这远非微不足道。如果你进行闭气实验，你会惊讶地发现，如果你进行复杂的计算，你的成绩会显著下降。因此，无论有意还是无意，闭气潜水员在潜水时都习惯于不思考。如果他成功地不去想任何事情，他的表现会更好。这样做，他无意识地使用了冥想技巧（佛教、印度教、瑜伽）的初步知识。

鼓励门徒冥想的导师会告诉他们：“抑制思绪的流动”。会发生什么？我没有能力告诉你。要么冥想让人接触到超越性的精神活动，改变他们的意识状态，要么大脑可能将氧气输送到通常较少供血的区域（在正常意识状态下，这些区域首先获得氧气）。结果是一种幸福感，任何闭气潜水员都会有。有效的闭气意味着幸福感，否则它就不有效，因为只能在不思考的状态下进行。

在通过不思考达到精神启蒙或涅槃之前，闭气潜水员喜欢自发地这样表现，这在压力或困扰时对你有好处。当然，闭气潜水让你还能欣赏水下景观的美丽。但对许多潜水员来说，这种神秘维度基于一个客观现实，只有少数人意识到。

从身体机器的能力来看，潜水员可以达到30米的深度，进行1分半钟或2分钟的闭气。一些“特别有天赋”的人甚至可以做到更多。这项活动就像俄罗斯轮盘赌。这些“超人”只是随意地缩小了他们与致命昏厥之间的差距。

那么，你能做什么？彻底宣布闭气潜水是一项高度危险的活动，或者尝试找到一个折中的办法？

在涉及数字之前，应先了解情况。例如，疲劳会大大增加危险：也可能是因为过度劳累、缺乏睡眠、任何导致疲劳的原因。

当我大约20岁时，我习惯在假期进行闭气潜水。冬天时，我有时会进入一个50米长的游泳池（巴黎的图雷尔游泳池）。我身体状况很好，所以我能够用脚蹼在1米深的游泳池中游过（这相当于下潜到20米并回到水面）。在这么浅的深度进行闭气可能看起来很安全。这是个大错！当时，我正在为进入高等学院的入学考试做准备。我睡得很少，工作很努力。我认为游泳会对我有好处。我开始在空荡荡的游泳池中潜水。我以前经常这样做，但只有在身体状况良好的时候；那天我有点累。幸运的是，我正游向浅水区。我从未到达游泳池的边缘。大约在40米处，我突然昏倒，没有任何征兆。我对事件毫无记忆。我猜有人发现我浮在水面上，生命垂危，并发出了警报。我恢复意识时，已经在游泳池的边缘，被救生员救了回来。

想象一下，如果我游向相反的方向会发生什么。图雷尔游泳池有一个10米高的跳板，它悬在5米深的深水区上方。如果我朝深水区下潜，我可能会在跑动中下潜并在此时昏倒。人体的浮力取决于深度。即使肺部充满空气，压力会压缩它们，这会减少阿基米德浮力的等效测量。

因为我在1米深的地方昏倒，我自然地回到了水面，即使在途中失去了一点空气。在几米深的水下，我会直接下沉；我将不再那么容易被发现，当有人在游泳池底部看到我时，就太晚了。

一旦昏厥发生，大脑细胞就不再获得氧气。问题在于它们的自主性并不大。如果溺水者在冰冷的水中经过长时间的浸泡后被救起，这仍然很罕见。我们可以认为，一个人在大约5到10分钟内完全没有氧气，就彻底死了。

你可能注意到，当救援人员对溺水者进行口对口人工呼吸时，他们不是用大气中的空气，而是用他们呼出的空气来为肺部通气。他们希望这能更快地恢复呼吸反射，而呼吸反射是由二氧化碳水平控制的。

为什么我们有“呼吸的倾向”？很简单，因为随着时间的推移，血液中的二氧化碳水平增加，当它超过阈值时，延髓（接收信息）会立即触发吸气动作。否则，人们应该有意识地决定呼吸，或者他们会昏倒。

如上所述，疲劳会增加闭气的危险，这些危险始终存在。寒冷也是如此。在较冷的水中，心率会升高，细胞的新陈代谢也会增加。为了发挥泵的作用，心脏也会消耗一些宝贵的氧气。在冷水中，即使穿着潜水服，结果也会下降。闭气的严重问题在于，没有人能知道在特定时间和设置下截止时间是什么。问题“今天，在我身体状况和水温的情况下，我能在昏倒前闭气多久？”除非……你亲身体验，否则无法回答。很可能，很多人在几秒钟内濒临死亡，却根本没有意识到。

在潜水过程中，每一次突然的努力都会导致氧气的过度消耗，使其水平低于致命的阈值。这就是我的朋友乔索40年前在科西嘉岛去世的原因。我们1960年在巴黎的航空高等学院是同学。乔索习惯于和鲁巴克斯一家潜水。德·鲁巴克斯夫人曾是射鱼比赛的女子冠军。他们所有人都热爱射鱼和科西嘉附近的海洋，而如今的海洋已不再如此丰富。乔索潜水是合理的。至少他是这么认为的。但有一天，当他下潜到十几米时，他射中了一条栖息在石头上的石斑鱼。乔索滑入了裂缝，并努力将鱼从它的藏身之处拉出来。所需的氧气消耗导致了致命的昏厥。

一个训练有素的潜水员如果附近有人一直盯着他并能立即帮助他（不会成为第二个溺水者），可以达到15或20米的深度。射鱼比赛不能在10米的深度进行。富含鱼类的水域，尤其是在我们的地区，意味着更深的水域。选手们通常成对潜水。每名队员轮流下潜，由另一名队员监督。但单独的深水闭气潜水无异于俄罗斯轮盘赌。

我们上面提到过氧气的分压。实际上，氧气进入血液的转移率取决于靠近血细胞的分子密度。密度越高，转移率越强；这很合理。因此，当专业潜水员下潜到非常深的水下（超过100米）时，他们使用的呼吸气体中氧气的百分比设置得比通常的20%要低得多，否则氧气会变得过于氧化。从使用呼吸设备开始，想要用纯氧瓶潜水的人会抽搐。当氧气浓度太高时，氧气就像一种毒素。

当潜水员在20米深的水下闭气时，他所承受的压力是大气压的三倍。因此，即使肺部空气中的氧气含量较少，血液仍可能得到氧气供应。由于压力是三倍，氧气分子的密度也是三倍，因此氧气的流入保持稳定。

当潜水员上升时，情况正好相反。人体不仅对血液中氧气水平的下降作出反应，还对氧气流入的下降作出反应。事实上，当潜水员上升时，他从三到四倍于大气压的压力下降到接近大气压的水下表面。血液的流动随之下降。这就是为什么许多致命的昏厥发生在潜水员上升时。一些专家甚至提到“9米昏厥约会”。

因此，当潜水员在深度时，即使他肺部的氧气不足以让他活着回到水面，他也会感觉很好。如果他只是认为自己是个超人，他不会及时决定上升，而会因自己的疏忽付出生命的代价。

从几米的深度开始，空气（在肺部或潜水服的肺泡中）的压缩会使他产生负浮力。在上升时昏倒的人不会到达水面，而是直接下沉。

让我们明确一点。如果你应该记住这篇文章中的一件事：深水闭气不是一项运动，而是一件血腥的愚蠢事情。闭气没有取得任何进步。人类机器仍然一样。只是人们不再远离灾难，比如距离灾难一分钟后，而是以一种鲁莽和病态的方式接近它。那些进行长时间闭气或单独深水闭气的人只是在与死亡调情，因为他们会在致命昏厥前几秒浮出水面，无论他们是否意识到这一点。

最好的情况是，你只是被警告并侥幸逃脱。最坏的情况是，无法挽回。

大约15年前，一场对深水自由潜水的狂热兴起。两个人直接导致了这一现象。其中一个是潜水员雅克·马约尔，另一个是电影导演吕克·贝松。

二战后，一旦闭气潜水发展起来，人们就想知道自己能走多远。一些“超人”在成绩上展开竞争，特别是吉利亚特·恩佐·马约尔。毫无疑问，没有人能与闭气潜水相提并论。一个人的极限不一定与另一个人相同。但无论如何，极限是存在的，一些冠军因达到自己的极限而失去了生命。在高风险运动领域，闭气是一项，显然没有比认为自己高于其他人类更危险的了。这适用于许多其他活动，比如徒手攀登，没有任何保护措施等。

马约尔转向了一种不同的表现方式。他不是自己下潜到越来越深的水下，而是被一个固定在电缆上的重物拉下去。

他借助一个充气的气球上升，始终避免任何体力劳动及其氧气的过度消耗。凭借这种技术，马约尔成为第一个在“自由潜水”中超过100米深度的人。为了完成他的壮举，有一串潜水员在下潜过程中配备了气瓶。如果发生昏厥，其中一名一直密切关注他的潜水员会立即把他迅速带回水面。他可能最终死在床上。

这类活动的兴趣：并不大。当有人潜水时，肺部中的空气会被压缩。在10米的深度，胸腔体积减少了一倍（马略特定律：压力翻倍，因为10米的水相当于一大气压）。在100米的深度，肺部空气的体积减少了十倍。当时，有人担心肋骨可能会骨折。但实际上并没有发生这种情况。膈肌只是向上移动到肋骨之间。人们也已知在潜水时呼吸频率会减少。对马约尔进行的检查显示，这种减少是明显且迅速的，仿佛人体正在适应新的条件。

这主要是为了吸引媒体的注意。这些壮举比任何其他东西都更壮观。如今，没有人再对这些记录感兴趣，也没有人记得这个特殊项目的记录保持者的名字，它更像是一场马戏表演而不是一项运动。多年来，马约尔一直在使用一种不为人知的作弊手段，以实现长时间的闭气（三到四分钟）。在每次新的“壮举”之前，他会去安第斯山脉的的的喀喀湖进行潜水，那里空气中的氧气含量较低。血液会迅速改变并富含血红蛋白（血液成分在几天内发生变化）。如果马约尔在返回后的几天内尝试他的壮举，他的闭气能力会比那些不知道这个技巧的人显著提高。如今人们知道，东德人通过在完全封闭的体育场中训练运动员，使他们处于低氧状态，从而赢得了几项体育比赛。为了确保结果，运动员的血液被丰富起来。在户外，他们可以凭借这种“自然兴奋剂”赢得奖牌。

马约尔的成绩来自于冥想表演。他声称他跟随了一位禅宗和尚的启蒙。从水中出来后，我们的“僧侣潜水员”甚至对摄像师大喊“原始尖叫”等，令他们非常高兴。

电影导演吕克·贝松决定在银幕上展示雅克·马约尔的生活。他本人也是一名潜水员，并且与“海豚人”相识已久。结果是一部 cult film（邪典电影）：《大蓝》在全球取得了巨大成功。

不可否认，贝松是一位非常优秀的电影导演，他懂得如何选择镜头、灯光和演员。这部电影讲述了一个人对闭气的迷恋（马约尔接受了这个角色，使用他的名字，这是一个浪漫化了的他的人生故事）。电影中穿插了比赛和壮举。一个女人拼命试图让“英雄”远离他看似荒谬的深渊。在电影的最后场景中，她对“雅克·马约尔”说她怀孕了，但这不足以让他摆脱他的执念。我们看到他最后一次下潜，进入深水，黑暗占主导地位。一些海豚加入他，这位“海豚人”消失在黑暗中，远离了聚光灯。

Homo Delphinus（人鱼）也是雅克·马约尔几年前出版的一本书的标题。他坚信人类来自“游泳的猴子”，并不断有机会提出他的理论。这部电影和这些荒谬的想法在全球范围内造成了500起伤亡，尤其是在年轻人中。在法国，一家名为**Apnea**的杂志被创建，解释了“极限潜水”的基本知识。这场灾难的受害者之一：我的儿子让-克里斯托夫，他在1990年夏天在马赛附近溺水身亡。他23岁。

我教他从小就开始潜水，我们在世界各地的海洋中进行射鱼（以及闭气），特别是在加勒比海和红海。但凭借我自己的经验，我从一开始就警告他这项活动的严格限制。尽管他有良好的天赋，我们从未下潜超过约12米，也没有超过30秒。因此，我们远未达到我们的实际能力。在我不知道的情况下，

《大蓝》

这部电影（我后来得知他看了五次）最终吸引了我的儿子。根据我们在船上找到的《Apnea》杂志中提到的“技术建议”，他迅速增加了他的闭气深度和时间，但没有告诉我这个变化。他去世的情况揭示了这些荒谬想法对潜水界的影响。

我的儿子遇到了皮埃尔·沃格尔，一位店主，他拥有一家名为“老潜水员”的商店。沃格尔现在已经去世，是这一地区潜水的先驱之一。1990年7月的一天，他带着我的儿子乘船去查看位于马赛附近的一艘30米长的沉船“圣多米尼克号”。沃格尔大约60岁，仍然使用呼吸设备潜水。那天船上共有五个人：我的儿子、圣让医生（一位对潜水问题有深入了解的医生）、埃伯斯霍尔德教授（一位德国的雅克-伊夫·库斯托，撰写了多本关于潜水的书籍）和一位名叫巴里略的巴西人；他们都是一名经验丰富的潜水员。埃伯斯霍尔德带着他的青少年儿子，那天没有潜水。四名潜水员装备了潜水服和气瓶，在抛锚后向“圣多米尼克号”的桥下潜去。当他们在沉船周围游动时，我的儿子开始在闭气中进行30米深的“笛卡尔恶魔”潜水，并与他们一起。埃伯斯霍尔德随后在沉船的后甲板附近为他拍了一张照片。他们中没有人对我的儿子的行为感到担忧。事故发生后，皮埃尔·沃格尔发表了这些评论（我请求他允许我记录我们的谈话）：

- 闭气已经取得了很大进展[...]。这与你所知道的完全不同。现在有很多潜水员进行射鱼或在这样的深度潜水。我们密切关注顾客，但让我们朋友做他们想做的事[...]。

看到一个年轻潜水员在他们附近进行30米深的闭气并没有让这三位五十到六十岁的男人感到担忧。他们只是继续潜水，不再关心他。潜水结束后，他们进行减压阶段。只有在他们取下所有装备后，沃格尔才第一次询问埃伯斯霍尔德的儿子关于“潜水员”。

• 不，我有一段时间没看到他了，少年回答（船离海岸几英里远）。

在极度恐慌中，三个人重新装备自己，试图通过海标（从海岸上取下的标记）将船停在沉船上方。同时，他们已经抛锚，船移动了。当他们找到我儿子的尸体时，尽管圣让医生做出了努力，但已经太晚了。

虽然我先后与四位潜水员取得了联系，但我从未得到一个连贯的事故版本。沃格尔最初似乎非常自信，但他开始隐瞒第四位潜水员（巴西人）的存在（“我们有三个人：圣让、埃伯斯霍尔德和我……”）。我打电话给德国人，当他问我是在什么情况下为我死去的儿子在沉船甲板上拍照时，他含糊其辞。我知道第四位潜水员的存在是通过圣让医生得知的。当我再次与沃格尔联系时，他变得慌乱（“哦，对了，我记得了，我们有四个人……”）。当然，我的儿子并不是犯罪的受害者，但很明显，那四个人对那天发生的事情并不感到自豪。

你无法改写过去或改变人们的想法。但当时，四位经验丰富的潜水员，他们并不是潜水新手，其中一位是医生，他们认为单独的深水闭气潜水是一件无关紧要的事情，没有引起任何反应。

这起事故之后，世界各地接连发生了许多类似事件。马约尔继续他为自由潜水所做的奋斗。没有记者对这个问题感兴趣。相反，电视节目却展示了各种自由潜水的壮举，比如尼古拉斯·于洛在没有安全头盔的情况下驾驶微型飞机。我记得有个人声称自己能在游泳池里潜水四分钟。这足以让人产生从事这项运动的念头……

现在我们必须得出一个结论：自由潜水危险吗？我们是否应该禁止它？

我们已经看到，危险始终存在，那就是在没有任何征兆的情况下突然晕厥。

如果潜水员疲劳，或者水温较低，这种危险会增加十倍。将自由潜水作为“极限运动”是一种完全的荒谬行为，就像俄罗斯轮盘赌一样。人体没有取得任何进步。与其在远离晕厥的情况下进行这项活动，例如将自由潜水时间严格限制在约30秒，即使是那些最“有天赋”或受过训练的潜水员也如此，而“冠军”们却只是在死亡边缘徘徊。

在良好的身体状态下，经过逐步的适应，使用良好的装备（特别是防寒潜水服）：30秒，10米，双人潜水，始终关注你的同伴，这是合理的。在再次潜水前至少等待五分钟以恢复体力。此外，你应该限制进行这项活动的时间，因为自由潜水非常耗体力。如果你状态良好，高强度的自由潜水本身也可能因疲劳而使你陷入严重危险。

严重的问题是，没有任何媒体对这个话题感兴趣，尤其是在夏季之前，他们本应提醒潜水员。更严重的是，杂志编辑（马约尔）、电影制作人（贝松）等人却参与鼓励年轻人不顾后果地拿生命冒险。指望像《大蓝》这样的电影在片头加上一段简短的警告信息是徒劳的。但死亡并不会吸引媒体的注意。人们更愿意谈论“极限运动”。没人会展示溺亡者的苍白尸体或裸手上升运动爱好者的残缺身体。当一个知名人物因从事这种活动而死亡时，人们急忙说他“死得其所”，并用一些陈词滥调来掩盖在空中飞人表演者被聚光灯刺瞎双眼后，血溅在舞台上的惨状。这是一种奇怪的方式，让人做着梦。

在我儿子去世几个月后，在法国南部，我遇到了一位年轻的面包师，他习惯在深水中使用鱼叉捕鱼。他经常下潜到30米深，并参加比赛，因此他经常和搭档一起训练。我们见面不久后，他被发现倒在30米深的海底，已经没有了生命迹象。根本不需要再警告他一次。

这个人很幸运。

那些带来利益的死亡

当我儿子在30米深的水下进行自由潜水时去世，他留下了一期《自由潜水》杂志，其中有一篇文章介绍深水自由潜水。当你看到想要进行这种活动所面临的风险时，你不禁会想知道是什么促使年轻人继续这样做。当然，电影《大蓝》产生了巨大的影响：当这部电影上映后，每个国家的自由潜水事故都急剧增加。在最近一期《自由潜水》杂志上，标题是“《大蓝》问世十年后”。

不可否认的是，自由潜水确实有其迷人的地方。问题在于，那些像皮埃尔·沃格尔十年前所说“自由潜水取得了很大进步”的人，通常并不了解他们所面临的风险。协会当然建议双人潜水，因为同伴随时可能帮助晕厥的潜水员。但同伴并不能在所有情况下都救起潜水员。我在《自由潜水》上读到，有些潜水员甚至在38米的深度从掩体中猎杀鱼类。在这样的深度，哪个“超级同伴”能救起一个因晕厥而失去意识的鱼叉手？记住，晕厥是瞬间发生的，没有任何征兆。受害者无法启动任何救援设备。

让我们稍微分析一下在深水处救援晕厥者的问题。在30米的深度，人体和潜水服承受着4个大气压的压力。氯丁橡胶潜水服中包含一些空气。任何潜水员都记得，当他下潜到60米深处时，他的6毫米潜水服会因压力而变得像纸板一样薄。

在30米的深度，潜水员所携带的每种气体（包括肺部和潜水服中的空气）的体积都会减少四倍。即使潜水员在水面上有正浮力，他在水下也会有负浮力，必须努力才能上浮。这种负浮力大约是几公斤。
如果救援者试图将他失去意识的同伴从30米深的水下拉上来，他不仅会达到自己的极限，还必须拖着双倍的重量上浮。当然，他可以丢掉他们两人的配重带，但在这种悲剧性的时刻，是否每个人都能保持冷静？和朋友一起潜水的人是否曾想过这个问题？有多少人努力检查过救援晕厥潜水员是否可行？

在我将这份关于自由潜水的文件上传到网络后，一位《章鱼》杂志的记者联系了我。他的一位最好的朋友习惯于在深水中与同伴一起使用鱼叉捕鱼。他突然晕厥，而他的同伴无法将他带回水面。他选择向附近的一艘船求助，但为时已晚。请记住，神经元不能承受超过10分钟的缺氧：这非常短暂！

当你看到你所承担的风险时，再次问自己，为什么还要追求成绩？如果你阅读像《自由潜水》这样的杂志，你会了解到“静态自由潜水”的世界纪录现在已经超过了……七分钟。顺便问一下，“静态自由潜水”比赛是什么样子的？

就是这样！你可以看到参赛者躺在游泳池的浅水区，或者更准确地说，是在其浅水区，深度为30厘米。在比赛过程中，他们的背部会浮出水面。上述比赛中最好的成绩是6分22秒。当我看到这样的照片时，我不禁会问，使用游泳池有什么意义？普通的更衣室难道不够吗？

就在上面，奥运选手们只需将脸部浸入洗手池中。

说实话，潜水行业必须继续下去。几十年来，很多事情都发生了变化。前几天，我在远离海岸的一个非常有名的地点（具体来说是马赛附近的埃马利亚德群岛）进行潜水，过去那里可以看到美丽的海绵、海玫瑰（细胞珊瑚）和许多海洋奇观。我只看到被几代学生潜水员翻耕过的荒凉海底，他们每个人都试图从自己的潜水活动中带回一些东西。我甚至不谈野生动物，它们如今与50年代甚至60年代时的状况已毫无关系。我不知道这些海底是否还能恢复往日的丰富。

为了不空手而归，使用鱼叉的潜水员率先下潜到更深的地方。过去，自由潜水员所处的世界充满了奇妙的动植物。十米或十五米深的地方，是一个真正的丛林，你可以遇见体型巨大的居民。如今，没有了巨大的海绵，这是地中海的特色之一，也没有了珍珠贝（有些长达一米）。海洋的典型居民现在是海胆。因此，一种新的运动被推广：自由潜水，被视为一种独立的活动。如果没有品牌强大的赞助（防水手表、水下装备等），这些壮举不会引起如此大的反响。上面我们提到过这个“项目”的先驱者：马赛人雅克·马约尔。他牵着猪下潜到100米深。我们现在已经不在那个阶段了。根据《自由潜水》四月刊的报道，这些壮举最初进展缓慢。在突破性的100米之后，进展变得微乎其微：102米，然后是104米，等等。

人们和媒体对这些微小的进展感到厌倦。正如你可以在《自由潜水》本期第66页看到的：“再深两米也不会带来金钱。”说媒体就是说广告。赞助商要求更壮观的进展。这个项目中的领军人物是弗朗西斯科·费雷拉，绰号“皮平”。使用鱼叉，挂在气球上上浮。

顺便说一句：这相当于在一分钟半内将一个人压缩在17个大气压下，然后在同样时间内进行减压。但是，一个人被绑在重物上向深渊下潜的画面更具吸引力，也更令人毛骨悚然。人们喜欢马戏团的游戏。

2000年1月15日，皮平第一次尝试下潜到162米。他采用了一种技术，即溺水自己的鼻窦。但天气很糟糕，轻微的水流让他游回了起点。协助潜水员已经下潜，但由于减压阶段的长度，他们无法在那么深的地方停留太久，而我们的“自杀式自由潜水者”不需要进行这些减压：他的潜水时间太短，不足以让氮气溶解在血液中。“皮平只有一分钟的时间来通风！”（意思是：关闭由血液中二氧化碳水平上升控制的警报装置，见上文）。他下潜了，但在离水面四米的地方晕倒了（“这是由于他尝试前的努力造成的”）。
没关系！医疗团队认为他可以在第二天再次尝试。第二天，他再次尝试。根据皮平的说法，“这是通往200米的公开邀请”，凭借他溺水鼻窦的技术，他承诺将披露这一技术，使补偿变得更快。在这种情况下，使用流线型的配重罐，为什么不设想有一天达到300米甚至更多呢？

这样，未来看起来很光明。媒体和赞助商都会跟进。许多人将购买皮平创造纪录所用的脚蹼或潜水服。

“静态自由潜水”发展了。如今，许多城市的人们聚集在俱乐部中，把鼻子贴在市政游泳池的底部。联合会、官方认可、会议、媒体报道……每个人都可以梦想有一天成为纪录保持者，享受聚光灯的照射。不需要有强壮的肌肉，良好的起跳：一切都取决于你的头脑。

- 安全不是一个有利可图的市场……

反应：

在我将这篇文章上传到我的网站几天后，我收到了一些反应，全部都是正面的。最初的一些反应来自年轻人，他们写道：“先生，我和我的朋友们进行了深水自由潜水。我们并不知道这一切，现在我们意识到我们可能多次接近死亡却毫无察觉。”
一家潜水学校告诉我，他们将我的网站链接放在他们的网站上，以教育他们的会员。他们指出，潜水俱乐部充分利用了《大蓝》的影响，因为会员人数显著增加。
诚然，但自由潜水相关的致命事故数量在该电影发布后的第一年估计增加了五百多起，而该电影中约有五十人遇难。

通过读者劳伦·拉特瓜格，这篇文章被刊登在《章鱼》八月刊上。确实，其中一位记者刚刚失去了他最好的朋友，这位朋友在自由潜水事故中遇难。他当时正在深水中使用鱼叉，由他的同伴看护。在一次过长的潜水后，他上浮时晕倒，掉落在海底；他的同伴无法将他带回水面。他随后寻求帮助，但徒劳无功。我希望这篇文章的传播在去年夏天拯救了一些生命。我也希望一家潜水装备公司会对这个为自由潜水晕厥者设计的救援系统项目产生兴趣。如今，每个潜水员都把他们的气瓶固定在充气背心上。过去，梅·韦斯特是一种笨重的奢侈品；如今，它们更加简洁。为什么自由潜水者不能拥有同样的安全呢？

2000年5月18日

来自法国圣莫尔的杜哈梅尔先生的一封电子邮件：*

尊敬的先生，

我非常惊讶地发现，当我还在一所工程师学院时，我经历了和您一样的经历。我习惯在游泳池中潜泳50米。有一天，在圣欧昂游泳池，我躺在池底（就像您在最浅的一端那样），却没有注意到任何异常。我记得我不得不努力才能游到泳池的尽头，然后我躺在池边恢复了意识。与此同时，一位跟随我演示的朋友惊讶地看到我仍然在水下，他起初以为我还有呼吸，然后因为我不动，他叫来了救生员，救了我。和您一样，我也是自由潜水的幸存者。*

2000年11月

我收到了来自法国鱼叉协会董事会成员的一封电子邮件。他首先提醒我一件非常重要的事情。过去，自由潜水者会进行过度换气，即每隔两秒进行一次呼吸，持续一到两分钟。这种方法非常有效，可以清除肺部中二氧化碳含量较高的空气。当你进行这种过度换气时，你会感到头晕，这说明它起作用了。这样做，你的血液会接触到这种二氧化碳含量较低的空气；因此，血液中的二氧化碳水平会下降，但正是这个水平让你感到“缺氧”。这样，自由潜水者只是关闭了他的警报系统，他只能根据自己估算的时间来决定结束潜水。潜水员被建议禁止这种强制换气，并用“连续深呼吸”代替。但这其实是一样的：如果你进行多次深呼吸和强制呼气，肺部的空气就会被新鲜空气取代。

然后，他在邮件中附上了一个我认为非常有趣的建议。使用鱼叉的潜水员应该成对进行（但正如我们在《章鱼》记者的故事中看到的，同伴可能无法救起他的朋友）。我的同事建议给两位潜水员配备一种由二氧化碳补充气瓶充气的救生衣，但由于晕厥没有任何征兆，当他的朋友晕倒时，同伴会触发它。救援装置可以通过无线电触发。缺点是无线电波在水中传播效果不好，但超声波可以，并且很容易产生。这种系统可以戴在手腕上。更进一步，希望监控自由潜水者活动的父母或朋友可以随时观察他，并在任何时刻将他带回水面。

设计一个由电力驱动的“守护天使”似乎并非不可能。深度计-微处理器的结合已经运作良好（因为潜水电脑已经存在）。微处理器有一个时钟，可以计算潜水时间。剩下的就是将这个系统与烟火触发装置结合。有能力开发这种系统的最合适的公司是那些自己生产潜水电脑的公司。如果您感兴趣或能帮助我们，请随时给我发一封电子邮件。

一个有趣的变种是简单地修改潜水电脑：只需在上面安装一个插孔，使其成为自由潜水者的安全设备。

技术解决方案并不缺乏，缺乏的是制造这些产品的意愿。令人惊讶的是，例如，贝查特公司（Beuchat）并不对此感兴趣，尽管他们赞助自由潜水比赛队伍。

2000年11月14日

我转载了来自留尼汪岛的自由潜水者朱莉的故事。没有评论。*

尊敬的先生，我不是一个寻找有利可图项目的大型工业家，但我仍然有权给您写这几句话。我20岁，名叫朱莉·戈蒂埃，我从事顶级自由潜水，并参加了10月份在尼斯举行的上届自由潜水世界锦标赛。我从10岁起就和父亲一起进行鱼叉捕鱼，他教会了我一切。自从我开始进行自由潜水后，我在鱼叉捕鱼方面取得了很大进步。我38岁的叔叔对我取得的成绩非常自豪并感到印象深刻。有一段时间，他甚至和我和父亲一起参加我们的远征。10月29日，我父亲和他各自单独下潜。他们在30米深处滑行，等待金枪鱼。当他的背部朝上时，我的叔叔停下来射击。我父亲随后下潜去帮助他，拿着鱼叉枪并注视着他。一切正常。当他到达水面时，我父亲没有看到我的叔叔，于是向下看，发现他正直线下沉。他背朝下时晕倒了。我父亲立刻下潜去救他，但我的叔叔至少有175磅重，而且超重。他面朝上，正往下沉，看着我父亲的眼睛。他紧紧抓住那根仍然支撑着的生命线。面对命运让他在自己生命和两人死亡之间做出选择，他努力游回水面。他的耳膜破裂了，不得不丢掉腰带。第二天，潜水员发现了我叔叔的尸体。我知道您能理解我的悲伤。我想与您分享，因为和您一样，我认为应该发明一种系统来防止如此多的事故。我从您那里找到了我对未来的恐惧的答案。我希望您的项目能成功，以防止其他人经历我们所承受的痛苦。
真诚地，

朱莉，电子邮件：julie.c.gautier@voila.fr *

从2001年9月15日起，连接次数： * * ---