White beaches, crystal clear waters, blue skies, and great people enjoying some holiday vibes. It seems that some of the best conditions, environments, and circumstances for diving, are also some of the best for drinking.
After a days diving, there’s nothing wrong with relaxing and watching a sunset with a cold beverage of your choice. However, as with everything in scuba diving there are certain limits we need to abide by in order to stay safe underwater, and alcohol consumption is one of them. Alcohol has many physiological and psychological effects, (many of which we enjoy!), and therefore it is important to understand how these may effect us underwater.
1. Alcohol is a diuretic, and therefore causes dehydration within the body. In combination with a loss of water through immersion diuresis, heavy sweating in hot climates or hot exposure suits, and the dry air we breathe from our tanks, this can put our body at a serious risk of dangerous dehydration; which in turn is a leading risk factor of decompression sickness.
2. Alcohol is also a vasodilator and causes our blood vessels to dilate, meaning we lose body heat a lot faster by conduction and convection from any exposed skin. Not only will this be uncomfortable and cold underwater, but maintaining our body temperature becomes even harder and can lead to feeling tired and fatigued. Loss of body heat will in turn change our circulation, increasing the risk of decompression sickness and hypothermia, both of which we want to avoid while diving.
3. Another physiological effect of alcohol is that it reduced our blood sugar levels, raising our risk of hypoglycemia. This in itself is inherently dangerous, but even more so underwater where we cannot regulate our blood sugars and any loss of consciousness will likely lead to a drowning situation. Even small reductions in blood sugars will leave you feeling tired and fatigued after a dive where our bodies metabolism speeds up whilst surrounded by a cold aquatic environment.
4. There are also the obvious psychological effects of alcohol; reduced concentration, reduced awareness, lack of inhibition, poor judgment, slower reaction times, reduced coordination etc. These may be both safe and enjoyable within moderation around a bar with some friends, however any mental or bodily impingement is very dangerous underwater and will seriously affect how you prevent or react to an emergency. We should never drink and drive for such reasons, and therefore we should never drink and dive!
So… as scuba divers should we avoid alcohol altogerther?
No. Alcohol is both safe and enjoyable in moderation and you’d be hard pressed to find a diver or dive professional that doesn’t enjoy the occasional drink after a great day under the sea. Refrain from drinking AT ALL before a dive, as it’s seriously dangerous to be diving under both the physiological and psychological effects of alcohol. Only drink moderately after diving, as heavy consumption can increase the risks of dehydration and decompression sickness. Finally, if any drinking before a days diving leaves you feeling groggy or hungover, you should cancel or postpone the dive until you’re fully recovered.