Beer While Diving? There have been recent assertions in scuba magazines, chat rooms and scuba forums that it’s OK to drink beer between dives during a surface interval. Some divers insist on drinking beer before, during and after their dives. Is there any danger in drinking alcoholic beverages and diving? The short answer is that by drinking alcohol before and during diving trips a diver severely endangers not only himself but his buddy! A study by Perrine, Mundt and Weiner found (scuba) diving performances significantly degraded at blood alcohol levels of 40 mg/dl (04%BAC). They also cite a clear increase in the risk of injury at this level which can be reached by a 180 lb. man who ingests two 12 oz. beers in 1 hour on an empty stomach. This very pertinent study once again points out that there is a diminished awareness of cues and reduced inhibitions at relatively low levels of blood alcohol. Their study used well trained divers who were being paid to do their best as their diving performances were being videotaped. Blood Alcohol Concentration (BAC) Research has shown that there is a definite reduction in the ability of the individual to process information, particularly in tasks that require undivided attention for many hours after the blood alcohol level has reached 0.0%. This means that the risk for injury of a hung-over diver is increased significantly, particularly if high BAC levels were reached during the drinking episode. The AMA upper limit of the BAC for driving a vehicle in the US is 0.05%. Surely diving with any alcohol on board would be foolish, considering the alien environment (water) and the complex skills required to follow no deco procedures. Alcohol Impairment All of the following behavioral components required for safe diving are diminished when alcohol is on board or has been on board in the prior 24 hours: Reaction time Visual tracking performance Concentrated attention Ability to process information in divided attention tasks Perception (Judgment) The execution of psychomotor tasks. The individual who has alcohol onboard may not feel impaired or even appear impaired to the observer but definitely is impaired and this is persistent for extended periods of time. The use of alcohol, even in moderate doses, clearly carries a self-destructive aspect of behavior and leads to higher probabilities for serious accidents. Alcohol is a diuretic In addition to these dangers is the definite danger of alcohol-produced dehydration. Dehydration is considered to be one of the prime causes of decompression illness. Alcohol in any form has a direct effect on the kidneys, causing an obligatory loss of body fluids. If your drinking buddy is an intelligent diver, surely he will understand that this is not preaching - a cool beer is appreciated by the author - but by drinking and diving he can turn a safe sport into a nightmare for himself and his family. I’m sure that when he considers that he is also endangering his buddy that he will think twice before drinking alcohol before and while diving. My friend, Dr. Glen Egstrom, PhD has stated the problem succinctly: He made personal review of over 150 studies on the effects of alcohol on performance has resulted in the following observations: 1. Ingestion of even small amounts of alcohol does not improve performance: to the contrary it degrades performance. As Lieber has stated in his study on the effects of small amounts of alcohol, “alcohol can never make you do a thing better, it can only make you less ashamed of your mistakes.” 2. While there are variables that can speed up or delay the onset of the effects of alcohol, they are minor issues which do not overcome the decrements to the central and peripheral nervous system. 3. Alcohol can be cleared from the blood at a predictable rate. Generally on the order of .015% BAC per hour. This does not necessarily mean that the decrements in performance have been completely eliminated in that time. 4. Alcohol is a depressant drug that slows certain body functions by depressing the entire central nervous system. Effects are noticeable after one drink. 5. The effects are mood elevation, mild euphoria, a sense of well being, slight dizziness and some impairment of judgment, self control, inhibitions and memory. 6. Increases in reaction time and decreases in coordination follow the dose/response curve quite well. 7. Alcohol is involved in 50% +/- of all accidents involving persons of drinking age. 8. The deleterious effects of alcohol on performance are consistently underestimated by persons who have been drinking alcohol. 9. Divided attention tasks are found to be affected by alcohol to a greater degree than those tasks with single focus of concentration , i.e. a task such as a headfirst dive into shallow water, with many interrelated decisions necessary to a successful dive, will be impacted to a greater degree than lifting a heavy weight.