Smoking & Welfare Policy
Scuba Diving and Smoking
Are Not Compatible
Black Turtle Dive operates a strict no-smoking policy across all dive boats, pool areas, and dive premises — for the health of our divers, our team, and the ocean we work to protect.
All Dive Boats
Swimming Pool
Dive Office
2 Hours Before & After Diving
"Smoking before or after a dive is not a lifestyle choice — it is a physiological risk that directly compromises your safety, your dive buddy's safety, and the health of every person around you. This policy exists to protect everyone on board."
The Policy
Where Our No-Smoking Policy Applies
Black Turtle Dive's no-smoking policy covers all areas where our guests, staff, and students are present. This policy applies to cigarettes, cigars, pipes, roll-ups, vapes, and e-cigarettes without exception.
No SmokingAll Dive Boats
No smoking at any point during a boat trip — departure, transit, surface intervals, or return. The confined deck space means every person on board is exposed to second-hand smoke, putting divers' lung function at risk before they even enter the water.
No SmokingSwimming Pool Area
No smoking in or around the pool. Our pool is a training and practice environment. Carbon monoxide and airborne toxins from cigarette smoke affect all students and instructors present during training sessions.
No SmokingDive Office
No smoking inside or immediately outside the dive office. This is the primary reception and check-in area where students and staff gather before and after every dive day.
No SmokingBriefing Areas
No smoking in or around the dive briefing room. Briefings take place immediately before boat departures — any smoke exposure at this point directly compromises diver safety before entering the water.
No SmokingEquipment Storage
No smoking near dive equipment storage or kit assembly areas. Cigarette ash, tar residue, and airborne compounds contaminate regulators, BCDs, and mouthpieces used by other divers.
No SmokingRinse Areas
No smoking near equipment rinse tanks. Cigarette ends and smoke residue contaminate the rinse water used to clean shared gear after every dive, affecting all equipment cleaned in the same tank.
The Science
Why We Ask You Not to Smoke for 2 Hours Before and After Diving
The two-hour window around a dive is the most physiologically critical period for a diver's body. What you put into your lungs in the hours before and after entering the water has a direct, measurable effect on your ability to safely manage gas exchange, nitrogen off-gassing, and cardiovascular demand.
Why Two Hours?
Carbon monoxide from a single cigarette remains bound to haemoglobin for up to two hours, directly impairing the oxygen-carrying capacity of your blood and your body's ability to off-gas excess nitrogen after a dive. Peak nitrogen bubble formation occurs 40–50 minutes after surfacing — and smoking during this window dramatically increases decompression sickness risk.
The Nitrogen Off-Gassing Problem
The Nitrogen Off-Gassing ProblemWhen you surface after a scuba dive, dissolved nitrogen continues to leave your tissues for up to two hours. This process — off-gassing — depends entirely on healthy circulation and oxygen-carrying capacity in your blood.
Smoking after a dive causes vasoconstriction (narrowing of the blood vessels), reduces available oxygen in the bloodstream, and slows nitrogen elimination — increasing the risk of nitrogen bubbles forming in joints, tissues, and the nervous system. This is decompression sickness (DCS). It can cause joint pain, paralysis, and in severe cases, death.
Diver Physiology
How Smoking Directly Harms the Scuba Diver
Scuba diving relies on efficient gas exchange, healthy cardiovascular function, and clear airways. Smoking systematically undermines every one of these requirements.
Reduced Lung Capacity
Smoking destroys alveolar walls, reduces diffusing capacity, and produces excess mucus that clogs airways. A compromised respiratory system means less air per breath, faster cylinder consumption, and shorter bottom time. In an emergency, it means less physiological reserve.
Carbon Monoxide Poisoning
Carbon monoxide binds to haemoglobin 220–290 times more readily than oxygen. At depth, where partial pressures are already elevated, this effect compounds. A diver who has smoked before a dive has measurably less oxygen available — reducing performance, increasing fatigue, and impairing decision-making underwater.
Elevated Heart Attack Risk
Smoking causes vasoconstriction, atherosclerosis, and platelet activation. Heart failure is the number-one killer in scuba diving. Submerging a cardiovascular system compromised by smoking — in cold water, at pressure, under physical exertion — significantly elevates the risk of a cardiac event underwater.
Decompression Sickness
Nicotine-driven vasoconstriction reduces blood flow through peripheral vessels, impairing the body's ability to eliminate dissolved nitrogen. Elevated fibrinogen and clotting factors in smokers' blood further increase DCS risk. Narrowed vessels that cannot eliminate nitrogen create the conditions for bubble formation and serious injury.
Bronchoconstriction & Air Trapping
Smoking causes airway inflammation and bronchoconstriction. Underwater, air trapping in inflamed airways creates conditions for pulmonary barotrauma during ascent: trapped air expands, potentially rupturing alveoli and forcing gas bubbles into the bloodstream or pleural space.
Impaired Neurological Function
Chronic CO exposure causes deterioration of nervous system activity — compromised judgement, slower reaction times, and reduced ability to manage emergencies. Combined with the narcotic effect of nitrogen at depth, a smoking diver faces compounded cognitive impairment that non-smokers do not experience.
Equalisation Problems
Smoking paralyses cilia — the microscopic hairs that clear mucus from sinuses — causing chronic congestion. Congested sinuses and Eustachian tubes create equalisation problems on descent, increasing the risk of ear and sinus barotrauma. Attempting to dive while smoking-congested is one of the most common causes of ear injury in recreational divers.
Pulmonary Embolism Risk
Smoking elevates plasma fibrinogen and clotting Factor XIII, increasing blood coagulation activity — an established risk factor for pulmonary embolism. In the diving context, where gas bubbles are already forming during decompression, elevated clotting activity creates conditions for embolic events that can be rapidly fatal.
Your Fellow Divers
Second-Hand Smoke on a Dive Boat Is Not a Minor Issue
Why Boats Are High-Risk Environments for Second-Hand Smoke
Why Boats Are High-Risk Environments for Second-Hand SmokeA dive boat is a confined space. Guests sit close together for extended transit between sites. Limited deck air circulation means prevailing wind frequently directs smoke directly toward other passengers. Non-smoking divers exposed to second-hand smoke during a 45-minute boat ride arrive at the dive site with elevated carboxyhaemoglobin levels, reduced oxygen-carrying capacity, and elevated decompression risk — all imposed on them by someone else's choice.
This is not a preference issue. Black Turtle Dive's no-smoking policy on all dive boats is the direct expression of our duty of care to every guest on board. We do not allow one person's smoking habit to compromise the physiological safety of other divers who have no way to remove themselves from exposure.
The same logic applies at the pool and dive office. Airborne cigarette toxins in a training environment affect the respiratory function of students and instructors who have diving sessions immediately ahead of them.
Vaping & E-Cigarettes
Does the Policy Apply to Vaping?
Yes — Vaping Is Included in This Policy
E-cigarettes and vaping devices are included in Black Turtle Dive's no-smoking policy. Vaping delivers nicotine, which causes the same vasoconstriction that impairs nitrogen off-gassing and elevates DCS risk. Many vaping products also deliver ultrafine particles and aerosol compounds into the lungs that affect airway function.
The scientific evidence on vaping and diving is still developing — but the precautionary principle is clear: any inhaled substance that compromises cardiovascular function, airway integrity, or blood oxygen-carrying capacity before or after a dive is a risk that this policy addresses. The same two-hour window and the same location restrictions apply to vaping and e-cigarettes as to conventional cigarettes.
Equipment & Hygiene
Smoking and Dive Equipment Hygiene
Beyond the physiological risks, smoking near dive equipment creates direct hygiene and equipment integrity issues that affect every person who uses shared gear.
- ✕Cigarette ash and tar residue contaminate regulator mouthpieces shared between students and staff
- ✕Smoke particles settle on BCD oral inflation valves, creating hygiene risks for every subsequent user
- ✕Airborne tobacco compounds affect the sealing surfaces of mask skirts and regulator diaphragms over time
- ✕Smokers' hands carry tar and nicotine residue that transfers to shared equipment including cylinder valves and BCD buckles
- ✕Cigarette ends near rinse tanks contaminate the water used to clean and maintain shared gear
- ✕Cigarette smell on a person transfers to the mouthpiece they breathe through — an unnecessary experience for any diver using shared regulators after them
The Bigger Picture
Smoking, the Ocean, and What We Stand For
Black Turtle Dive is a conservation diving centre. Our mission is to build divers who understand, respect, and actively protect marine ecosystems. Every student who passes through our doors is introduced to the reef not as a tourist attraction but as a living system that requires active stewardship.
Cigarette butts are among the most common items of marine debris retrieved from reef surveys worldwide. Filters are made of cellulose acetate — a plastic material that takes up to ten years to degrade and leaches nicotine, arsenic, lead, and other toxins into the marine environment as it breaks down. A single cigarette butt can contaminate one litre of water within an hour of contact.
A diver who cares about coral restoration, marine life biodiversity, and the long-term health of Koh Tao's reef systems aligns naturally with a smoke-free diving environment. Our no-smoking policy is not an imposition. It is an expression of the same values that bring our students to us in the first place.
Policy Summary
All Dive Boats Swimming Pool Dive Office Briefing Areas Equipment Storage Rinse Areas
Pre-Dive Post-Dive
Vaping / E-CigsBOOK COURSES – PRICES
