Despite its popularity and appeal, the sport of scuba diving is nevertheless surrounded by numerous myths and misconceptions. These myths are often fuelled by mass media (think movies like Jaws) and are consequently spread through word-of-mouth.
So what are these scuba diving myths and what is really going on? Let’s demystify a few common ones.
Myth 1: Divers have to be expert swimmers
Basic swimming skills are indeed necessary (after all, scuba diving is a water sport) – if you can swim a short distance on the surface and stay afloat for a few minutes, that is all you need. There is no need to be an Olympic swimmer – scuba divers barely make any physical effort underwater, just like astronauts in space do not need to exert themselves to move through space.
Myth 2: Scuba diving is dangerous
Like any other sport, scuba diving is not 100% devoid of risks. However, if you follow simple safety rules and guidelines and don’t dive beyond your comfort level and ability, you will avoid any potentially dangerous situations. Scuba diving is a very safe sport. Statistically, you are much more likely to get into a car accident on your way to the dive site than to ever have an accident underwater.
Myth 3: Scuba divers use oxygen tanks
Recreational scuba divers do not use oxygen tanks / cylinders; instead, they use regular air or, sometimes, enriched air, with a higher percentage of oxygen than normal air. Technical divers, on the other hand, use various breathing gas mixtures, such as Trimix (a mix of oxygen, nitrogen and helium) and pure oxygen. As a side note, regular air we breathe contains only 21% oxygen of which we consume approximately 5% with each breath and exhale the remaining 16%.
Myth 4: Pressure will crush a diver’s body
Our bodies are made mostly of liquids and solids which are not compressible under pressure. Gas, however, which is contained in the air spaces in our bodies, such as our ears, sinuses and lungs, is compressible. Divers breathe compressed air at ambient pressure, which means their lungs are not squeezed by pressure on descent; sinuses equalize by themselves while ears are easily equalized by pinching the nose and blowing slightly through it.
Myth 5: If you ascend too fast, you can explode
If you ascend too fast, you can develop decompression sickness (bubbles of nitrogen gas forming in various parts of a diver’s body). This is easily preventable: plan a no-decompression dive, dive the plan, ascend no faster than 9 metres per minute and make a recommended safety stop. It’s like driving – if you exceed the speed limit, you are putting yourself at risk. If you respect safety rules, nothing will happen and, surely, you will not explode, unless you are an actor in a Hollywood blockbuster.