Alcohol, hydration and diving: what the research says

In the study DAN cites (Perrine et al.), the ability to perform scuba skills was significantly compromised at a blood alcohol concentration of 0.04%. DAN notes that situational awareness and protective inhibitions may drop even at lower levels.

DAN lists recent alcohol, seasickness, traveller's diarrhoea, heavy sweating, diuretic medicines and air travel as causes of dehydration in divers. Dehydration, especially when severe, is a potential risk factor for decompression sickness — and its symptoms, like fatigue, can be confused with DCS.

DAN says alcohol may enhance the effects of narcosis. Together, alcohol, dehydration and narcosis can reduce problem-solving ability underwater — exactly when you need it.

Drink regularly on the boat, especially in the Egyptian summer. DAN notes good hydration may help prevent cramps and fatigue, but over-drinking is not the goal — DAN also warns that hyperhydration can contribute to immersion pulmonary oedema.