Smoking and Diving

Last year I was on a dive boat where – for the first time in my experience – the majority of divers smoked cigarettes between dives. We’re taught in basic OW class that smoking & diving is bad so I decided to research exactly why it’s so detrimental to a diver’s health in particular. I don’t want to ‘lecture’ about the merits/politics of smoking. I want to communicate the physiological effects which are evidence-supported – not theories – in an effort to educate. Addicted smokers will find a way to rationalize away all of these findings, but these effects are well documented and supported by diving medical experts:

• Carbon Monoxide (CO) binds to hemoglobin 250x tighter than oxygen. This prevents hemoglobin from carrying O2 from the lungs to the cells and CO2 from the cells to the lungs. The smoking diver is more hypoxic and any stressful situation – entering or exiting the water? – puts the diver at increased risk for a hypoxic-related event, such as a heart attack.


• Nicotine causes a short-term increase in blood pressure, heart rate, and flow of blood from the heart. It also causes arteries to narrow. The reduced O2 blood combined with the effects of nicotine will create an imbalance in the demand for oxygen and the body’s ability to supply.


• Obstructions in the lungs, caused by chronic pulmonary disease attributed to smoking, markedly increase probability of pulmonary barotraumas and arterial gas embolisms.


• Many smokers have nasal and sinus drainage problems – this increases their chances of middle ear and sinus blocks and squeezes.


• Cigarette smoke in the nose paralyzes the movement of cilia – the microscopic ‘hairs’ that are supposed to trap foreign particles – for approximately 1 hour after one cigarette. In chronic smokers, the cilia is completely destroyed. Thus smokers' noses are not able to clear dirt, bacteria or other debris as effectively, which promotes infection.


• Chronic smoking damages the lungs so that the surface area where gas exchange takes place is reduced. Unfortunately, the non-active person uses only 25% of their lungs and they can smoke until over 75% of their lungs are destroyed before they will notice shortness of breath in daily activities.

Thanks to Dr. David Sawatzky (“The Diving Doctor”), Dr. Paul S. Auerbach, Dr. Ernest S. Campbell (“Scuba Doc”), Diver’s Alert Network and Dive Training magazine for their articles on the web. They were consistent, insightful and in easy-to-understand language.