Dangers of SCUBA

The effects of breathing high pressure gas, is one of the major dangers associated with scuba diving. The general hazards associated are summarised below:

• Decompression Sickness
  Prolonged exposure to breathing high pressure gas at depth will result in increased amounts of inert gases, usually nitrogen, dissolving in the bloodstream. All divers must avoid the formation of gas bubbles within the body. This is commonly known as decompression sickness or ‘the bends’ and to be avoided, the diver must always ascend slowly allowing the gases trapped in the bloodstream to gradually break and leave the body.This is done by controlling the speed of ascent and making periodic stops to allow gases to be eliminated. Making safety stops (also known as decompression stops) and ascending slowly using dive computers or decompression tables for guidance is the ideal way to help eliminate the build up of gas.Decompression sickness must be treated immediately, usually with the use of a recompression chamber. Administering enriched-oxygen breathing gas or pure oxygen to a decompression sickness diver on the surface is a good form of first aid, although death or permanent disability may still occur.

• Nitrogen Narcosis
  Divers who breathe high pressure gas at depth can also suffer from nitrogen narcosis, which is a reversed change in consciousness, similar to alcohol intoxication. Being ‘narced’ (as commonly referred to) can impair a divers judgment and make diving very dangerous.Nitrogen narcosis usually starts to affect some divers at 66 feet (approx. 20 metres) and manifests itself as a slight dizziness. The effects increase significantly with increases in depth. Almost all divers are able to notice the effects by 132 feet (40 meters). At these depths divers may feel euphoria, nervousness, anxiety and loss of coordination and a lack of concentration. Hallucinogenic reactions and tunnel vision can also occur at extreme depths.Whilst nitrogen narcosis can occur quickly, it can also disappear quickly during the ascent; where divers often failing to realise they were ever affected. In short, it affects individual divers at varying depths and conditions, even altering from dive to dive.

• Oxygen Toxicity
  Oxygen toxicity occurs when oxygen in the body exceeds a safe ‘partial pressure’. In extreme cases it affects the central nervous system and can cause spasms, which can result in a diver spitting out his mouth piece (regulator) and drowning. Oxygen toxicity is preventable provided one never exceeds the established maximum depth of a given breathing gas. At depths greater than 180 feet (approx. 55 metres), divers are advised to use alternate gas mixtures containing a lower percentage of oxygen (hypoxic blends).

For a more formal and general list of hazards associated with scuba diving please visit the following post – Risks Associated with Scuba Diving