Diving places high demands on your body. This particularly affects the heart, circulation, and lungs. At the same time, smoking is one of the most common preventable risk factors for many diseases. But what actually happens when the two come together? How harmful is smoking for divers?
Smoking itself is harmful. That’s no longer a secret nowadays.
You can feel the effects of smoking in everyday life and especially during exercise. However, they can be much more significant when diving, because additional factors come into play in scuba diving. These include higher ambient pressure, the uptake and release of nitrogen in the body, and increased breathing effort.
It almost seems paradoxical: the breathing gas in the tank is checked down to the last detail, yet just before the dive, a cigarette is quickly smoked. While every contamination in the tank is meant to be avoided, you voluntarily introduce harmful substances into your own body.
Smoking does not affect just a single organ, but multiple systems at the same time:
Cardiovascular system
Nicotine increases heart rate and blood pressure and constricts blood vessels. This puts additional strain on the heart and can impair oxygen delivery. As a result, nitrogen elimination is reduced, because if your circulation is impaired, your body breaks down nitrogen more slowly. This can increase the risk of decompression sickness.
Lungs and respiratory system
Smoking leads in the long term to increased mucus production, irritated airways, and impaired self-cleaning of the lungs. A weakened lung means you breathe less efficiently. Anything that impairs the lungs can also be problematic when diving.
One risk is that inflamed or mucus-filled airways can cause air to become trapped in the lungs. This can be dangerous during ascent and, in the worst case, lead to injury.
With reduced lung function, the elimination of CO₂ is also impaired. Elevated CO₂ levels can lead to increased stress, greater breathing effort, and stronger narcotic effects underwater. This can impair performance and increase the risk of nitrogen narcosis and hypercapnia, especially during more demanding or deeper dives.
Oxygen transport in the blood
Carbon monoxide from cigarette smoke reduces your blood’s ability to carry oxygen. This is because carbon monoxide binds to hemoglobin about 200 times more strongly than oxygen does. As a result, binding sites are blocked, and your blood can carry significantly less oxygen.
Is it enough not to smoke before diving?
The short answer: no! Some effects, such as an increased heart rate or constricted blood vessels, can last up to 24 hours, and long-term damage to the lungs persists regardless.
That means even if you don’t smoke right before diving, the effects can still play a role.
What do PADI and others say about smoking?
PADI does not generally prohibit smoking. However, it does play a role in the medical self-assessment: if you are over 45 and smoke, you need a medical fitness-to-dive examination.
Global Underwater Explorers (GUE) takes a much stricter approach. A very high standard of fitness and health is required. Smoking or vaping is not compatible with this standard, which in practice means you cannot take courses or dive in the GUE context as long as you smoke.
What does that mean in practice?
This leads to some clear recommendations for divers:
- Do not smoke right before the dive under any circumstances
- Reduce smoking or, ideally, quit altogether
- Dive more conservatively (e.g., shallower and with longer surface intervals)
- If you can’t refrain from smoking, get a medical examination before diving
Conclusion
From a medical perspective, the combination of diving and smoking is not ideal. The lungs, cardiovascular system, and the transport of oxygen and nitrogen are particularly affected. These are precisely the areas that are especially important in diving.
Anyone who wants to dive more safely should take smoking as a risk factor seriously and avoid it if possible.
At Scuabanana we place great importance on health, safety, and mindful diving. That is why we clearly stand for a responsible approach to one’s own body—and for us, that also includes refraining from smoking. Smoking is prohibited in our dive center to ensure a pleasant and healthy environment for all guests and staff.
