Scuba diving can be a nerve-wracking activity. Sometimes people are tempted to take a few swigs of liquid courage (alcohol) to calm their nerves and be more relaxed for their dive. However, scuba diving and drinking alcohol are two activities that should never mix. There are already many risks involved with scuba diving, and drinking alcohol adds even more. In this article we will discuss why you shouldn’t drink alcohol before or after scuba diving.
- Alcohol’s Behavioral Effects
- Alcohol’s Physical Effects
- How Much Alcohol is Too Much?
- Decompression Sickness and Alcohol
- Hypothermia and Alcohol
- Nitrogen Narcosis and Alcohol
- Heart Disease and Alcohol
- Alcohol Consumption Before Scuba Diving
- Can You Drink Alcohol After Diving?
- Scuba Diving with a Hangover
- Should You Mix Alcohol and Scuba Diving?
Alcohol’s Behavioral Effects
It is well-known that even a little bit of alcohol can affect a change in one’s behavior. There’s a reason why it’s called liquid courage – it impairs one’s judgment and loosens their inhibitions. It’s often used for social situations where you want to loosen up and make a heck of an impression. In a social setting, being confident and fearless is seen as a positive trait. Yet, it is for this exact reason that getting a little buzzed for a dive is a bad idea.
Scuba diving is a risky activity that requires a clear mind and an abundance of caution. There are safety guidelines to follow and a certain amount of problem solving to ensure each dive is successful. After consumption of alcohol, you are more likely to take risks and to recklessly push your limits. It may not even register in your mind when you’ve committed a safety violation such as ignoring your depth limits, no-decompression limits, or even air limits. Your judgment and decision-making skills will be impaired, and this can lead to fatal consequences.
Alcohol’s Physical Effects
Even sporadic and casual consumption of alcohol can produce short-term effects on the mind and body. It takes the liver approximately one hour to metabolize one standard drink of alcohol, and alcohol’s effects can linger for up to 8 hours. Most dives only last one hour or less, meaning a diver who has consumed alcohol prior to diving (even the night before) may be experiencing its effects for the entirety of the dive.
The potency of alcohol also depends on various factors, such as the individuals’ gender, weight, liver function, and age. Thus, the effects can be mild to severe, from skin flushing to nausea or vomiting. We’ve already discussed how alcohol can impair judgment and concentration. Some of the physical effects of alcohol include:
- Loss of coordination.
- Dulled perception, particularly vision.
- Reduced core body temperature.
- Increased blood pressure.
- Passing out.
Even if you consider yourself to be a heavyweight, or are someone who appears to experience minimal to no effects after having an alcoholic beverage, your central nervous system is still impaired whether you realize it or not.
How Much Alcohol is Too Much?
In a study, it was found that divers who had a blood alcohol concentration (BAC) as low as 40mg/dl was significantly impaired and made critical errors in judgment, as observed by sober divers, that they themselves did not realize. To achieve that level of BAC, all it takes is two 12-oz cans of beer consumed by a young (21-35), healthy adult male of average weight on an empty stomach to produce this kind of impairment in judgment.
The conclusion of that study was that alcohol should be avoided entirely before and between dives to maintain high performance levels in terms of coordination and judgment.
Decompression Sickness and Alcohol
Decompression sickness is one of the greatest risks of scuba diving, and the primary function of our dive computers is to help us avoid experiencing its effects. However, when you add alcohol to the mix, not even a dive computer can save you. You want to avoid decompression sickness at all costs, and alcohol doesn’t do you any favors.
Alcohol can drastically increase one’s risk of getting the bends. It is a diuretic, which means it causes your body to release its fluids faster via urination. If you are not replenishing your fluids (which you aren’t while scuba diving), then you will get dehydrated. This, in turn, makes your blood thicker, reducing its flow, and decreasing its ability to absorb and eliminate nitrogen. In other words, dehydration puts you at increased risk of decompression sickness.
There is also the possibility that alcohol can cause an increase of harmful nitrogen bubbles in the bloodstream. Alcohol can cause the blood vessels in the skin to expand, and the blood flow to those areas to increase (causing a flush). This results in nitrogen being absorbed to the bloodstream faster than dive computers and tables can anticipate, meaning you are at higher risk of decompression sickness even if you stay within your no-decompression limits.
Hypothermia and Alcohol
There is a misconception that alcohol increases your body temperature. In fact, the opposite is true. This misinformation was perhaps popularized by the tale of Titanic survivor, Charles Joughin, and how he famously got drunk and swam in freezing water until he was rescued. How did he survive? The theory is that “the water was cold enough to quickly tighten Joughin’s blood vessels and cancel out any effect of the alcohol”, according to this article by the National Post. We think it’s easier to chalk it up to a miracle.
As we mentioned, alcohol can cause an increased blood flow to the skin, causing a flush. The blood is being diverted from the body’s core, decreasing one’s overall temperature and putting them at increased risk of hypothermia. Water is 25 times more efficient at conducting heat away from the body, so the deadly combination of drinking and diving can cause you to freeze.
Additionally, alcohol will suppress your body’s ability to shiver, further making it hard to notice that you are getting really cold. Furthermore, post-dive drinking can decrease your body’s ability to regain warmth after surfacing.
Nitrogen Narcosis and Alcohol
Being drunk and experiencing the effects of nitrogen narcosis are very similar. Nitrogen, like alcohol, is a sedative which means it makes you sleepy. In the same way that pulling an all-nighter can impair your coordination and judgment much like someone who is drunk, too much nitrogen causes the same sensation.
Combine an excess of nitrogen and alcohol consumption, and you have a recipe for disaster. The effects of alcohol and nitrogen are cumulative. So your one drink at the surface can feel like two, three, or four drinks when mixed with the effects of nitrogen at depth. The deeper you dive, the worse the effects are. Nitrogen narcosis is already a risk for divers who are sober, so having a drink or two before a dive puts you at even greater risk.
Heart Disease and Alcohol
One of the leading causes of death while scuba diving are pre-existing medical conditions. If you have a heart condition, consider not drinking alcohol in general, particularly if you are heading out to a dive. If you suffer a medical condition on a dive, particularly if you’re diving alone, then you’re as good as gone.
Alcohol can dehydrate you, causing the blood to become thick and slow moving. This increases your risk for myocardial ischemia, which is when the blood flow to your heart is restricted to the point that it lacks oxygen and vital nutrients. When the blood flow is restricted too much, it can become a heart attack without any warning signs. Even being hungover can increase your chances of cardiac death.
Alcohol Consumption Before Scuba Diving
Even if you do not feel the effects of alcohol the next day, alcohol has been found to remain in the bloodstream for up to 8 hours after consumption. Thus, even having a few beers the night before a dive can still have lingering effects on the dive the next morning, which can increase the risk of DCS.
It is recommended that you wait at least eight hours or more between drinking and diving to give your liver time to metabolize the alcohol, and for any lingering side effects to go leave the body. Alcohol leaves the bloodstream slowly, and the more time you can give yourself to recover from its effects, the better.
Can You Drink Alcohol After Diving?
In theory, yes. It’s very normal to see dive professionals unwind after a dive with a few beers. Plus, you’re probably on vacation, so why deny yourself the pleasure when you’re supposed to be having fun? But before you do, there are a few things you have to keep in mind.
First of all,we recommend you wait four hours after diving before drinking so that all of the absorbed nitrogen in your body has time to be eliminated. As we mentioned earlier, alcohol can reduce blood flow, increasing the time it takes for your body to get rid of the excess nitrogen.
Second, the effects of alcohol can linger for up to eight hours after consumption. Even if you feel fully recovered, there is a possibility you are still impaired. To be on the safe side, we recommend waiting four hours after a dive to consume alcohol so that the nitrogen from the earlier dive can fully release. Then, wait eight hours for the effects of the alcohol you just consumed to dissipate. In other words, if you plan on drinking between dives, allot at least 12 hours for you to recover between dives.
Unfortunately, a downside to drinking between dives is that alcohol can affect your sleep quality. Even if you have completely sobered up before your next dive, you may have inadvertently impaired yourself anyways if you had a bad night’s rest. Diving while tired is much the same as diving while drunk, after all.
Third, alcohol will dehydrate you and you should consume plenty of fluids to make up for the loss of fluid. If you don’t realize that you are losing more fluid than you are consuming, then you are putting yourself at risk of dehydration for the next dive. Dehydration increases your risk of suffering from decompression sickness.
As long as you are aware of and planning around the lingering effects of nitrogen after a dive, as well as the lingering effects of alcohol after consumption, then you can safely drink alcohol after diving.
Scuba Diving with a Hangover
Do not be so inebriated from the night before that you are hungover the day of a dive. It is not an experience we recommend, and we say that from experience.
Alcohol increases stomach acid production and can lead to stomach pain, nausea, and vomiting during the hangover. These effects can be debilitating and will detract your focus from the dive. You may also feel fatigue, headache, shakiness, weakness, or worse during a hangover. It doesn’t help if the boat is rocky, and the undulating waves will make your head even dizzier.
Plus, if you have a hangover, you most likely are impaired in all of the ways described in the sections above. Therefore, the best thing to do if you are nursing a hangover is to take the day off and drink plenty of water.
Should You Mix Alcohol and Scuba Diving?
It’s tempting to share a few cold ones with your buddies after an amazing night out diving, especially if you are all on vacation. Unfortunately, the severe consequences of diving and drinking are so great that you should consider staying sober until after the trip is over.
Alcohol can cause impairments for up to eight hours after consumption. That means that if you want to drink before dives, that you should have ample time for your body to recover from its effects before embarking on a dive. Even if eight hours have elapsed, it’s good to keep hydrating yourself as much as you can before a dive, even if you feel fine.
If you even suspect that your mental or physical health are not in perfect condition as a result of alcohol, consider postponing the dive until the next day. The risks of consuming alcohol and diving are too great. It may be the first drink of the day, but it might just be the last dive of your life. You wouldn’t drink and drive, so don’t drink and dive.