Diving and Snorkelling

Occurs when an excessive amount of nitrogen in the body starts to form bubbles in blood vessels and tissues as the diver ascends. There is a higher risk if longer time periods are spent underwater, the dive was at depth or if the ascent at the end of the dive is too fast. The bubbles can obstruct blood flow to vital organs or cause serious tissue damage.  If you suspect you have decompression illness immediate hyperbaric oxygen therapy would be required.

Symptoms include:

Nitrogen narcosis acts like a drug, affecting individuals differently and is caused from breathing nitrogen under pressure usually at depth. Normally recreational divers are restricted to a 30m depth. It can affect a diver’s reasoning, memory, judgement, coordination and concentration. In some cases it can cause panic or anxiety or even lead to an over confidence in a diver with natural or normal survival instincts suppressed.

If a diver exhibits signs of nitrogen narcosis a safe ascent will help to mitigate the symptoms. The following factors may increase the effects of nitrogen narcosis including: poor visibility, excess carbon dioxide, fatigue or heavy work, anxiety or inexperience, the diver feeling cold, alcohol or use of drugs.

Carbon monoxide or oil contaminants in the air supply can be disastrous for divers.  Contaminated air causes a range of injuries and illnesses including loss of consciousness, convulsions or even death.  Air must contain oxygen and nitrogen only, in the right proportions.

Often occurring with snorkelers who hold their breath for extended periods of time, oxygen levels drop below a critical level causing hypoxia and a sudden loss of consciousness followed by a ‘blackout’. Snorkelers, especially those experiencing snorkelling for the first time, should be advised about Hypoxic Blackouts to avoid the risk.

A common contributor of diving and snorkelling deaths, panic can reduce a person’s capacity to think rationally and result in diving accidents. Equipment problems, personal factors such as physical unfitness or medical related issues, inadequate training or environmental problems can cause a diver or snorkeler to panic. Adequate and effective training prior to diving or snorkelling can help minimise this issue.

Existing medical conditions such as cardiac conditions, respiratory illnesses or conditions that can lead to a loss of consciousness such as epilepsy or diabetes, may become worse when diving or snorkelling. Many diving and snorkelling incidents are caused by existing medical conditions and participants need to know the risks and be adequately trained before taking part.

Whenever a person becomes incapacitated in the water, drowning may result. This could be from fatigue, through illness or injury, or from panic. It’s important to ensure you are medically fit to take part in a dive or snorkel, ensure you have the right equipment and receive adequate training and supervision or possess the experience needed to participate.

Caused by the pressure differences that change the volume in air spaces within the body, Barotrauma can cause damage to wherever air pockets are held in the body such as the ears, lungs, sinuses or face-mask cavity. External pressure may become greater than the pressure within the body and if a diver doesn’t equalise their ears on descent or ascent they can perforate their eardrum as a result.

When a diver ascends, the external pressure may become less than the pressure found within the body’s air spaces. For example, if a diver doesn’t exhale on ascent or makes a rapid ascent without exhaling properly to release pressure, their lungs may expand with gas causing lung tissue to be overstretched or tear. Sometimes gas may escape into the bloodstream and could potentially result in a stroke, neurological conditions or even death.