There are several reasons why you should avoid drinking alcohol and scuba diving.
1. You have to stay focused
During a dive, the situation can change quickly. Some days, the dive can be relaxed and easy while other days, it can be physically and mentally challenging. This can depend on the current, depth, duration of the dive or the distance swum. Dive conditions may even change from one hour to the next.
Therefore, it is necessary to always be able to react quickly. Alcohol impacts our ability to concentrate and our reaction time.
Alcohol can also make us feel overly confident, which may lead us to take more risks underwater.
2. You're risking Decompression sickness
You get more nitrogen in your system: Through an increase in peripheral circulation
Because alcohol increase blood flow, you could be absorbing
You get rid of it slower: Through dehydration
How funny that while being in water, dehydration is probably the number one risk factor for DCS and is already a problem for divers who did not consume alcohol: the pressure, the cold and the tight suit make you want to pee all the time! -> you’re losing liquid= dehydration
Alcohol has diuretic properties (makes you urinate even more)
Haven’t you wondered why pub’s toilets are always packed?
Hence you pee twice more and get dehydrated twice more.
Your blood is thicker, its circulation slower and the elimination of nitrogen bubbles altered.
That’s also why you should not drink too much alcohol even after dives as you are in the process of getting the nitrogen out of your system.
What should you do to stay hydrated?
When you go diving: before and after a dive, especially when you are on a liveaboard trip and do several days of diving, Drink plenty of water before feeling thirsty.
Attention: Drinking coffee, tea or sodas (or beer!) are not as good as drinking water.
It has been said that ideally we should drink one liter of water after every dive.
Eating yogurt, fruits and vegetables rich in water helps you fight dehydration as well as food rich in potassium such as bananas.
It is recommended to stop drinking alcohol (moderately) at least 8 hours before your next dive.
Avoid doing sport or sun bathing after the dives as they also make you more dehydrated.
For a diver, body heat loss is of significant concern. This is because in water, the body loses heat 25 times faster than in air. Alcohol is known to be a peripheral vasodilator; it makes blood vessels widen more than usual. As blood flows into the dilated vessels, it withdraws heat from the core to surface of the body; although this may bring about a flush of warm feeling, it is short-lived and predisposes the body to hypothermia. Research conducted recently out of Canada indicates that nitrogen narcosis is responsible for delay in shiver response, an important indicator of a considerable heat loss from the body, alcohol is also known to depress the response; complicating the heat loss problem further.
4. Drunken effect of alcohol and depth combine: you're losing it
The danger imposed here is that a diver may be unable to deal with an emergency, something which may land the diver into an accident.
Have you heard of the “martini’s law”? It states that every 15 meters a diver descends is equivalent in effect to drinking a glass of Martini. And of course both alcohol and nitrogen narcosis combine.
It has been proven that drinking alcohol, even the night before a dive, can increase the probability of harmful nitrogen bubbles forming in the bloodstream.
5. Drink with moderation
Drinking during your dive cruise is not prohibited, but you should be careful and drink with moderation. Furthermore, it is always better to drink when you can have a full day of rest to fully enjoy your dives. It is important to remember that it can be difficult to recognize the effects of alcohol on your body, so stay alert!