Alcohol, Nicotine & Divers – What You Should Know
By Dive Training
The last thing you probably want to read is another tirade on the dangers of drinking and smoking. Besides, what can I say that’s new? Although some recent evidence points to drinking alcohol in moderation as a health benefit, no one doubts the dire consequences of imbibing in excess. And no informed person on Earth doubts that smoking is merely a form of protracted suicide. But while we’ve known about these dangers for decades, many of us still drink — at least occasionally — and a quarter of us smoke.
Smoking and alcohol are so much a part of our society that we no longer even consider that both are essentially a form of self-prescribed drug administration. In fact, we describe drug use, smoking and alcohol as if they were distinct and unrelated activities. In reality, all that’s different is the substance in question, its effect and the form of administration. I won’t delude myself into believing that this article will make any significant dent in the statistics on alcohol or tobacco use. I believe that in a free society, people should be able to do what they wish, provided it doesn’t hurt anyone else. But there is one important proviso in the decision-making process that many ignore, and that is that the consequences of our choices can vary according to the circumstance in which we find ourselves. For example, it may be OK to drink, but not drink and drive. Diving is another case in point.
For us, the effects of alcohol and smoking go far beyond the normal concerns of heart attacks, or cancer. Those who venture underwater have additional concerns when our mental or physical capabilities are impaired. We also must consider factors that are irrelevant to nondivers such as heat loss and decompression. So, to make a responsible and informed decision about drinking and smoking, divers must first understand the unique effects that alcohol and nicotine present to us.
Diving requires surviving in a medium where heat is pulled from our bodies 25 times faster than it is in air. So no matter what the temperature, heat loss is a concern. It’s just a matter of degree. And who hasn’t been told that a great way to fend off the cold is with a good stiff drink? After all, alcohol feels so warm going down that it certainly must rekindle the internal fire, and give us that essential extra burst of energy, right? While it may sound logical, it’s just not true. Pharmacologically, alcohol is a peripheral vasodilator, meaning that it causes blood vessels in the skin to open up more than normal. As blood flow increases to fill the expanding vessels, we experience that warm, flushed feeling. But this momentary sensation is misleading because it masks a more sinister effect.
The blood flow responsible for that “warm and fuzzy” feeling is diverted from the body core. This loss of blood saps heat from a more vital area of our body and makes us more — not less — prone to hypothermia. Moreover, alcohol depresses shivering, the major symptom warning us of the onset of significant heat loss. There’s also a possible double whammy because some recent studies out of Canada have shown that nitrogen narcosis also delays the body’s shiver response. So, a predive drink or two compounds the heat loss problem, and post-dive alcohol consumption can impede the rewarming process. How much sense does it make to spend hundreds of dollars for an exposure suit only to reduce its effect by taking “a couple ’a belts”?
Bad as it is, problems don’t end with increased peripheral blood flow. Ironically, the blood vessels supplying our muscles do not dilate but constrict. This causes an increase in blood pressure, and is one reason those with hypertension are advised not to drink excessively. As muscle accounts for the greatest tissue mass in our body, this elevated blood pressure can place significant stress on the heart. Some believe this stress could be a contributing factor in the increasing number of diving accidents involving those with underlying heart disease.
Alcohol may also play a role in accidents blamed on poor physical conditioning. How so? Think back to the last time you had a few drinks. You probably didn’t feel a lot like exercising. This is partly due to mental impairment, but there’s another more direct reason for the feeling of fatigue; alcohol actually drains energy. One of the body’s primary fuels is sugar in the form of glucose, a substance produced by the liver. Alcohol consumption impedes the production of glucose, thus reducing our exercise ability far below normal. So, regardless of how you feel, an imbibing diver may be incapable of making the extra effort required to keep an unexpected situation from turning into an emergency. Alcohol also increases the likelihood of vomiting which, especially when diving, can easily lead to asphyxiation. So, in both the case of aggravating an underlying heart condition, or sapping our energy when it’s most needed, alcohol might be the final straw that tips the balance against us.
A Toast to Decompression
No one has ever established a direct relationship between drinking and any increased risk of decompression sickness. But prudent judgment tells us that, at least theoretically, such a relationship might exist. Most researchers who study the subject think it might work like this: We already know that alcohol consumption increases peripheral circulation. If you drink before diving, the increased blood flow could cause greater nitrogen absorption than that predicted by your computer (or tables). Therefore, this might increase your susceptibility to decompression sickness even if you are within the no-decompression limits. Some also believe that drinking could promote DCS in other ways, and point to alcohol’s diuretic (makes you urinate) property. The loss of fluid through urination contributes to dehydration. The decreased fluid volume, in turn, makes the blood “thicker,” reducing its circulatory efficiency and further altering the absorption and elimination of nitrogen.
The dehydration issue might also put divers at risk of the most serious form of decompression sickness, that with neurological symptoms (what’s sometimes called “Type II” bends). This is because the brain is especially susceptible to dehydration from alcohol consumption, and explains why a headache is the most common symptom of a hangover. It’s also important to understand that the effect of dehydration lasts even longer than the headache. This is why it’s particularly vital that anyone drinking alcohol the night before, even if they feel well the next morning, drink plenty of water prior to diving. Some researchers even argue that changes in blood flow caused by drinking after a dive could accelerate the release of nitrogen and indirectly enhance bubble formation. So it may be wise to avoid excessive drinking après dive.
Other researchers have suggested alcohol might actually contribute directly to DCS bubble formation. This, they contend, is at least theoretically possible because of alcohol’s ability to reduce surface tension. Surface tension refers to the tendency for a substance, such as a bubble, to exhibit properties resembling those of a stretched elastic membrane. The phenomenon is what’s responsible for the “skin” that seemingly arises on the surface of a pond or swimming pool, allowing a bug to literally walk on water. But surface tension is also important to divers from a physiologic perspective. It helps resist bubble growth in decompression sickness. So, anything that reduces the surface tension of a bubble could encourage the growth of bubbles that might otherwise remain too small to cause symptoms.
Indeed, this is all theory, but it may have an important role nonetheless. For example, many studies have shown that silent or asymptomatic bubbles are a common occurrence in divers (many of whom are nowhere near the normal no-decompression limits). This is especially the case for those who engage in multiple, repetitive diving, like when on a diving holiday. Common sense tells us, then, that even the theoretical possibility that drinking might push these silent bubbles to symptomatic bubbles shouldn’t be ignored. While the whole issue of alcohol’s contribution to decompression sickness is speculative, it’s still based on sound physiologic principles. If you do decide to consume alcohol, play it safe by following the guidelines contained in the sidebar.
I’ll Have Tee Martoonis, Please
A fact probably known only to scuba divers and anesthesiologists is that alcohol shares a property with the atmosphere’s most abundant gas, nitrogen. Both substances have the ability to sedate. In fact, the similarity between the symptoms of alcohol intoxication and nitrogen narcosis was, in the early days of diving instruction, the rationale for what was termed “Martini’s Law.” This “law” — actually a rough estimation, at best — stated that for every 50 feet a diver descends, his impairment from nitrogen is the same as drinking one martini at the surface. So, accordingly, a trip to 150 feet is equivalent to a three-martini lunch. Of course, if even a slight amount of real alcohol is added to the formula by predive drinking, the effect would be magnified (though by how much no one knows). Even diving accident reports appear to support the premise that alcohol and depth are an especially dangerous combination. Data from the Divers Alert Network (DAN) has long shown that 30 percent to 40 percent of injured divers admitted to consuming alcohol the night before, and 2 percent to 3 percent reported drinking just before diving or between dives.
The Nicotine Fit
There’s no need here to relate the dangers of smoking. Only historical tradition, and a strong lobby, would allow the legal sale of a product that killed one-third of the people who used it. Clearly, if its effects were immediate rather than long-term, the sale of tobacco would be as illegal as heroin, and tobacco executives would be the bunkmates of imprisoned cocaine dealers. But this discussion is about diving, so what additional risks face divers?
Some of the effects of smoking on divers are, like most other consequences, chronic — the result from long-term use. Various chemicals — primarily tar — from inhaled smoke cause chronic irritation of the bronchi, resulting in chronic bronchitis. The tar also destroys tiny hairlike structures called cilia that line much of the respiratory tract. Cilia are important because they conduct mucus from the lungs up and out of the airway. When they no longer function, the effect is retention of mucus and partial clogging of the airway, causing the classic symptom of “smoker’s cough.” But there’s a far greater effect on divers than an irritating cough.
Various poisons in the smoke also eventually destroy alveolar walls, which produces cavities in the lungs. The result of this process, excluding death, is a condition called emphysema. This form of emphysema, however, is unrelated to the disorder divers get from lung overexpansion injury. But noted diving medical authority Dr. Ernest Campbell said “Obstruction in the terminal airways and the emphysema that’s caused can — and does — produce air-filled dilations that can markedly increase your chances of pulmonary barotrauma and arterial gas embolism.”
Perhaps the most significant effect of smoking occurs long before any sign of emphysema, and it involves the restriction of air flow in the lungs. Smoking causes mucus retention and reduced alveolar flexibility that can easily cause air trapping deep within the lungs. Or, as Campbell puts it, “Smoking also causes an increase in bronchial mucous production with a concomitant paralysis of the cilia. Mucous plugs then become dangerous to the diver, setting the stage for air-filled sacs that lead to rupture upon ascent.” The result could be, and has been, pulmonary barotrauma in smoking divers who were breathing normally. So, assurance of safety from the first rule of scuba diving — always breathe normally — doesn’t necessarily apply to smokers.
Some of the chemicals in inhaled smoke do not remain in the lungs, but pass into the bloodstream. Their effect is to cause spasm and otherwise damage the walls of blood vessels. Damage is noted particularly in vessels supplying the heart, and thus is one of the reasons smokers are so prone to heart attacks. Other effects include stroke and various forms of peripheral circulatory disorders.
Of course, all this happens to people regardless of whether they dive. But for divers, there’s still more to be concerned about. Smoking just before diving results in reduced tissue oxygenation because the carbon monoxide (CO) in the smoke binds with hemoglobin 220-290 times more readily than oxygen does. The result is that a diver must work harder simply to maintain a normal level of activity. In other words, when someone smokes, they intentionally reduce their body’s ability to process oxygen. And just before entering the water seems an odd time for a diver to willingly lessen his ability to function at a peak level.
Again, Campbell puts the issue into perspective. “The effects of partial pressure on CO concentration in inhaled cigarette smoke would be the same as if the CO had come from some other source, such as the atmosphere or from oil-lubricated compressors.” He also relates the details, which are pretty startling. Acceptable CO level for diving is 10 ppm (parts per million) by volume (0.001 percent). A mere 10 percent to 20 percent increase yields a mild frontal headache, and just a 20 percent to 30 percent increase gives a throbbing headache associated with nausea. This is not a condition conducive to diving. Coma, convulsions and even death can occur with a CO increase of 50 percent to 80 percent beyond the maximum.
Of course, one’s CO level varies with the number of cigarettes smoked, the length of time since the last cigarette, how the cigarette was smoked and even the level of activity on that day. In heavy smokers, up to 15 percent of their oxygen is being replaced by carbon monoxide.
In terms of how smoking affects decompression sickness, no one really knows for sure. But most DCS susceptibility factors do involve changes in circulatory dynamics, and smoking has a definite effect on circulation. So, a logical but unproved conclusion is that smoking might increase the risk of bends.
The failure of the 18th Amendment proved how likely it is that we’ll ever put a stop to alcohol use. Smoking is perhaps an even greater challenge because its active agent — nicotine — is one of the most addictive substances ever discovered. Yet what sets us apart from other animals is our capacity to learn, and change our behavior when we know something could hurt us. Mixing diving with either alcohol or nicotine is a recipe for disaster, but if you still insist on rolling the dice, at least do so with your eyes fully open.
A Diver’s Guide to Drinking and Smoking
• Avoid drinking to excess anytime, but particularly before diving or while on a diving vacation.
• Avoid alcohol for at least 8 hours before diving (the same rule the FAA imposes on pilots).
• If you drank the night before, avoid diving if you feel a hangover, as you’re likely to be significantly dehydrated.
• If you drank the previous night, you may still be dehydrated even though you don’t feel a hangover. So, drink plenty of noncarbonated liquids — ideally, water.
• Avoid alcohol completely for at least one hour after diving, and even longer if you were diving deep (below 80 feet) or near a no-decompression limit. Avoid excessive intake even after the hour has passed.
• Of course, try to stop smoking. But if you can’t, try to abstain from smoking at least 12 hours before diving; and never smoke during a surface interval between dives.
• Search for a drug rehabilitation treatment center for treatment of drug and alcohol addictions.
A DAN Perspective on Diver Safety and Alcohol Use
By Joel Dovenbarger, BSN, vice president, medical services
Scuba diving is often perceived by the general public as being a remarkably simple activity, but in fact scuba requires that individuals maintain proper health, a certain level of physical fitness and the capacity to participate in exercise for a prolonged period of time. The sudden need for vigorous exercise during a surface swim or finding oneself in an unexpected strong current is always a possibility when diving. The lack of an appropriate physical response to these situations can be dangerous. Alcohol use will not make you stronger, it will not give you more stamina and it will not make you healthier.
Divers are responsible for maintaining their health and avoiding those injuries and accidents that occur in diving and everyday life. Few divers attempt to dive while intoxicated. This is not only dangerous, but deadly. Each year a few unfortunate individuals attempt diving after drinking heavily and end up as scuba fatalities.
It is not uncommon for a diver to have one or even two alcoholic drinks each evening on a scuba vacation. There may not be any negative effect from two drinks on one evening, as long as fluids are replaced with a like amount of noncaffeinated liquids. Dehydration in scuba divers is usually a cumulative condition that results after many days of losing fluid from scuba diving, being in a warmer climate, consuming beverages and food containing alcohol and caffeine, perhaps a bout of diarrhea or vomiting and the failure to replace fluids at a level over and above one’s normal consumption.
Although there is no causal effect between decompression sickness and dehydration or alcohol consumption, they are associated with many cases of decompression sickness. Both conditions can directly affect the amount of blood flow body tissues receive. This is especially true in areas with the tiniest of blood vessels. Body tissue depends on blood flow to deliver oxygen and remove waste products and nitrogen. Any condition which prevents this from occurring may increase the risk of nitrogen retention and possibly bubble formation.
There are other consequences of excessive alcohol use. The immediate effect of alcohol is to dull one’s senses. But did you know that those effects may continue well into the day after drinking?
In a study among two groups of pilots, alcohol use and performance were tested in a flight simulation. When a blood alcohol level of 0.10 percent was reached, impairment in abilities was easily documented eight hours after drinking. Additionally, individual susceptibility to the effects of alcohol was noted. This is not unlike what happens in recreational divers. Not only might we be influenced differently by the same amount of alcohol, but it is easy to lose track of the number of drinks one has during an evening drinking session on vacation. Having one or two drinks a day after diving may have no adverse effects for divers, but excessive alcohol consumption may very well produce negative outcomes.
In the final analysis, divers have to ask themselves, “Does excessive alcohol intake enhance my diving abilities or the beauty and enjoyment of recreational scuba diving?” The answer for responsible divers is no. The choice to drink before or after diving is up to each individual, but so is the responsibility to follow recreational diving safety guidelines, which include looking out for your dive buddy.
For divers, the effects of alcohol and smoking go far beyond the normal concerns of heart attacks, or cancer. Those who venture underwater have additional concerns when our mental or physical capabilities are impaired. We also must consider special factors that are irrelevant to non-divers such as heat loss and decompression.
Alcohol And Diving Do Not Mix
It is not advisable to drink alcohol after diving, as it can contribute to dehydration and will also negatively affect your judgment. Alcohol will also make you feel dizzy and lightheaded, which can be dangerous when diving. If you must drink alcohol, it is best to do so before diving, and not after.
How Does Alcohol Affect Diving?
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In the case of drinking before diving, the increased blood flow may cause a greater nitrogen absorption than predicted by your computer (or tables). As a result, even if you are within the no-decompression zone, you may be more prone to decompression sickness.
You are not permitted to drink alcohol while scuba diving. But why and what are the risks involved? What is the best way to drink alcohol after diving? In addition to decompression sickness, scuba diving with alcohol increases the risk of heart attacks. We dehydrate our bodies as a result of drinking alcohol and lower blood volume. Can you go out for a drink after diving? The theory is that yes. However, before you start the second session, it’s a good idea to rest for a few hours to get rid of the nitrogen that has built up in your system. Alcohol causes your stomach acid level to rise, resulting in stomach pain, nausea, and vomiting the next day.
Don’t Drink And Dive: The Risks Of Scuba Diving While Drunk
It is not a good idea to drink heavily after diving. It is not recommended to consume alcohol immediately following a dive because alcohol may have an impact on how our bodies remove the excess nitrogen that accumulates during our dives. Degenerative sickness is caused by dehydration, and drinking alcohol is one of the simplest ways to dehydrate oneself. It is safe to drive if it is safe to do so. In most cases, one standard drink takes up to two hours to process. You should wait at least three hours before driving after three standard drinks of alcohol. If you stop drinking, your alcohol levels may increase for up to 3 hours. What happens when you scuba dive drunk? However, if you are under the influence of alcohol, you may have a much higher risk of participating in the sport. A single drink can have a negative impact on your mental health and lead to physical harm. Drinking and diving present a number of risks, including increased nitrogen narcosis, heat loss, and impaired judgment.
How Long After Diving Can You Drink Alcohol?
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You should wait at least 24 hours after diving before drinking alcohol. Alcohol can cause dehydration and impair your judgment, both of which can be dangerous when diving.
There are numerous dangers associated with scuba diving, and drinking alcohol can also increase those risks. After consuming alcohol, you are more likely to take risks and push your limits too far. By impairing your judgment and decision-making abilities, you may result in death. A person’s risk of contracting the bends can be greatly increased by the consumption of alcohol. Dilatrate causes the body’s fluids to flow more quickly through urination. Drinking alcohol can cause blood vessels in the skin to dilate and blood flow to those areas (causing a flush). Alcohol has been linked to increased blood flow to the skin, flush, and cooling sensation.
It is possible to decrease the ability of your body to regulate its temperature following a dive. You are even more likely to be affected by nitrogen narcosis if you consume a drink or two before diving because nitrogen narcosis already poses a risk to sober divers. When you’re hungover, you’re more likely to die from a heart attack. Alcohol has the effect of slowing blood flow, increasing the amount of nitrogen in the body. When the blood supply to your heart is restricted, you are more vulnerable to myocardial ischemia. It’s no surprise that tired diving is as close to drunken diving as it can get. If you drink a lot of alcohol, you’ll dehydrate, so make sure you drink plenty of fluids.
Be sure not to be too drunk the night before your dive to be able to dive the next morning. It is not advisable to consume alcohol or dive. Alcohol can make you impaired for up to eight hours after consumption. Taking the day off to recover from a hangover is the best way to go about it. If you suspect you may have mental or physical problems as a result of drinking alcohol, postponing the dive may be the best option.
It is strongly advised that alcoholic beverages be avoided while diving or during a diving vacation. The same rules are in effect for pilots as they are for air traffic controllers. If you drink the night before, you’re more likely to be dehydrated than if you dive the next day, so don’t try to dive if you’re ill. The ability of free divers to hold their breath for more than 10 minutes without assistance is demonstrated by their ability to swim without the assistance of snorkels or scuba equipment. It requires a solid understanding of timing and practice to master this skill. If you’re interested in diving, especially if you’re a newcomer, you should schedule a time to discuss drinking and diving with your diving instructor.
Don’t Drink And Dive: Alcohol Increases Risk Of Decompression Sickness
The American Divers Medical Society (ADMS) advises that “anything other than heavy drinking” after diving be avoided. After diving, there are numerous health risks associated with drinking alcohol, including dehydration. Dehydration is one of the primary causes of decompression sickness, so drinking alcohol is one of the simplest ways to dehydrate yourself. After several days of diving, it is usually recommended that you wait 12 to 24 hours at the surface (for example, 15 hours if you’re going to a high altitude). If you have fully recovered from mild decompression sickness, you should not dive for at least two weeks.
Is It Ok To Drink Alcohol After Diving?
Most scuba diving organizations recommend that you do not drink alcohol for at least 24 hours before diving. This is because alcohol can dehydrate you, which can lead to decompression sickness. Alcohol can also affect your judgment and coordination, which can be dangerous when you are diving.
Can you drink scuba water with scuba gear? In this episode, Katy Jane Dives looks into this issue. Additional risks will be unavoidable if you drink and dive, so avoid doing so. The effects of alcohol on your system while diving can have lifelong consequences, and diving accidents may result from the effects of alcohol on your system. Excessive alcohol consumption can lead to behavioral changes as well. Alcohol can make you feel less inhibited and less capable of paying attention to what you are doing. If you have these factors in addition to your blood viscosity, your body will become thicker, increasing your chances of developing decompression sickness.
When you factor in the loss of inhibitions and increased risk of diving sickness, the risks associated with drinking and diving can be extremely high. Almost every diving expert believes that this is a perfect storm. You should be cautious when diving deep or in a new location. There are a number of myths and misconceptions about scuba diving and alcohol that must be dismissed. It is not true that you should wait several hours after drinking to dive. Even if you wait up to eight hours, your body may be too full of alcohol to survive a dive. Alcohol consumed by divers with DCS accounts for one-third of all consumed alcohol within 12 hours of diving. If you’ve had a dive, you can’t fully enjoy alcohol until the nitrogen in your system is completely gone. This is not a risk worth taking, in addition to heat loss, increased risk of decompression sickness, and lack of judgment.
Is It Okay To Smoke After Scuba Diving?
Smoking increases the risk of atherosclerosis, thrombosis, and high blood pressure in people with CVS for a long time. However, even short-term exposure to cigarette smoke can cause a temporary narrowing of blood vessels, also known as transient vasoconstriction. This may result in an incomplete reheat of the inert gas after a dive.
Smoking Before Diving Is Risky Business
Despite the fact that there is no absolute answer to whether or not smoking should be allowed before diving, the health risks are well worth considering. During scuba diving, it is possible to reduce tissue oxygenation by smoking just before the dive, resulting in a need to work harder to maintain a normal level of activity. Furthermore, the smoke from cigarettes contains carcinogens, which can harm divers in addition to the carcinogens. You should smoke before diving if you must; otherwise, you will be unable to dive.
Can You Drink Alcohol and Scuba Dive?
When you’re on holiday, it’s understandable that you may want to have a few drinks – many people enjoy drinking a cold beer before going for a quick swim or paddle! However, when it comes to scuba diving, you really do need to understand how alcohol consumption can present some very big hazards.
After all, scuba diving already carries a few serious risks that you’ll need to be aware of – whether you are a complete novice, or if you have been scuba diving for some time – these risks exist for everyone.
We learn about these risks throughout our training journey, from the very start of your Open Water Diver through to more technical dive courses.
What counts is how you choose to manage these risks.
Consuming alcohol before you dive is only going to see an increase in risk of injury and the encountering even more hazards. You could put yourself not only at risk of diving accidents, but the effects of alcohol on your system while diving could seriously damage your health for the long term.
Of course – I don’t want to spoil your perfect scuba vacation! But trust me when I say that drunk diving is really not a sensible thing for you and your dive buddy to do. Keep reading and I’ll explain why!
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Why Shouldn’t You Mix Drinking and Diving?
It’s reasonable to expect that a lot of people, scuba divers included, may choose to drink alcohol while on holiday or vacation. And if you visit any of the popular scuba diving destinations, such as those on the Thai islands like Koh Tao, there is a big party and drinking culture. However, drinking and diving brings on a few additional risks that you will certainly do best to avoid.
Alcohol increases the risk of accidents no matter what you do – and there are a few reasons why alcohol intoxication and diving are never going to mix well for your own safety – and others around you on your diving vacation.
Effects of Alcohol on Your Body
Below, I’ll go into a little bit of detail into how alcohol consumption affects your body during diving. For now, however, let’s examine your physical health under the influence of alcohol.
Ultimately, alcohol can dehydrate you – which is why it’s always important to drink plenty of water alongside your choice of alcohol on a night out and you’re diving the next day. Whenever you’re out diving, make sure that you have plenty of fresh water to drink.
Stay hydrated! Ensuring you are hydrated can also help reduce the chance of suffering with sea sickness, especially if you had a few cocktails the night before. If you suffer from sea sickness and want to know how best to manage it, take a read of my how to prevent seasickness when diving blog.
Excessive alcohol consumption can, of course, also lead to behavioural changes. Alcohol can help to make you feel less inhibited and less likely to pay attention to what you are doing. Your blood flow increases, and your judgement starts to decrease. Now imagine how easy it would be to accidentally ignore your no decompression limit, thus putting yourself at risk of decompression sickness (DCS).
It’s also extremely important to remember that your central nervous system is always going to feel the effects of alcohol, regardless of whether or not you have healthy blood pressure or feel absolutely fine. The golden rule and best case scenario is to not only avoid excessive intake of alcohol the night before a dive, but to avoid drinking it full stop.
Absorbed Nitrogen Increase
Although past studies have sometimes been a bit uncertain, it is sensible to believe that alcohol consumption could increase your risk of experiencing harmful nitrogen bubbles within your tissues, and from there, decompression sickness. That’s because of a perfect storm of increased peripheral blood flow, potential dehydration, and nitrogen absorption.
Your blood viscosity, too, is likely to increase which makes your blood thicker, and furthermore increasing your chance of DCS.
In fact, studies have actually shown that even nitrogen narcosis can become more likely at shallower than 30m if you dive after you consume alcohol.
Nitrogen narcosis is something that we all learn about, and many experience. The key is to recognise when one is feeling the effects of nitrogen narcosis, so that you can signal to your buddy and safely ascend a few metres. Now factor in being under the influence of alcohol. Could you be certain that you would recognise that moment and act appropriately? I very much doubt it, and that could lead into a downward spiral.
Excess nitrogen bubbles can be deadly – which is why drinking and diving can be extremely hazardous, especially when you factor in the loss of inhibitions and increased risk of decompression sickness, too. Dive professionals everywhere will tell you that it’s a perfect storm.