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  » First Aid  »  Diving Accidents
The majority of diving accidents involve recreational divers using self-contained underwater breathing apparatus (SCUBA).

Accidents usually take the form of near drowning, decompression ('the bends'), aural barotrauma (ruptured eardrum), pulmonary barotrauma (ruptured lung), facemask squeeze, and less commonly, nitrogen narcosis ('raptures of the deep' or 'the narcs').
Observance for DANGER takes precedence over all first aid activities and casualties or potential casualties should always be removed from the water prior to first aid assessment and treatment.

The recognition and first aid treatment of this condition is covered at length elsewhere in this book. All qualified SCUBA divers are required to show proficiency in the rescue and resuscitation of fellow divers, and the rescue of a near-drowned casualty should be effected by other qualified divers. Resuscitation should be effected immediately and a medical practitioner should always assess revived casualties to rule out the potential of further complications.

Commonly called `the bends', decompression sickness is caused by the formation of bubbles of gases (nitrogen) in the joints, circulatory system, and tissues of the body.

As the body of the diver is subjected to increasing pressures the deeper he or she dives; nitrogen in the air breathed is dissolved into the blood. Should the diver surface rapidly, the pressure on the body drops rapidly back to normal. This releases the nitrogen suddenly from a state of solution in the blood to form bubbles.
The bubbles thus formed usually block the small blood vessels and cause an embolism. This is especially dangerous when associated with the vessels in the brain. When similar blockages occur in relation to nerves in the limb joints or spinal cord, an attack of the bends is the result.

Signs and symptoms of decompression sickness may be all, or some, of the following: joint pain, dizziness, staggering gait, shortness of breath, itching of the skin, and sometimes partial paralysis. Onset is usually immediate, though prolonged onset of symptoms is common.

First aid treatment is to remove the casualty from the water, lay him or her horizontal. Urgent ambulance treatment is required. Should the casualty become unconscious, put him or her in the stable side position with head level and observe closely for changes to condition. Maintain body heat by covering with a blanket.

A diver presenting with identified decompression sickness requires recompression in a medical hyperbaric chamber. This is done under expert medical supervision, where he or she is recompressed, then gradually and safely decompressed to normal. This allows the nitrogen solution to escape back into a gas without forming dangerous bubbles.

Discourage attempts by others to take the diver back underwater to the original depth in a futile attempt at \recompression'. THIS IS DANGEROUS and merely compounds any 'bends' which the casualty has suffered.

Be aware that decompression sickness can manifest after air travel, where the body has been decompressed by altitude to a pressure less than `normal'. This causes a delayed reaction in the formation of bubbles.

An aural barotrauma, or ruptured eardrum, is caused by unequal pressure in the ear. Divers equalise pressure within the ear by flexing the eardrum with the valsalva manoeuvre; pinching the nostrils and 'blowing' into the nasal cavity. If a diver cannot perform this activity successfully, then the greater pressure on the outside of the eardrum will cause the membrane to rupture.

Diving Emergencies Signs and symptoms of a ruptured eardrum are; a momentary sharp pain in the affected ear, hearing impairment, vertigo, earache, and sometimes associated sinus pain.

A diver presenting with this injury should be referred to medical aid to avoid complications leading to potential deafness. First aid is to cover the ear with a pad, and discourage the application of eardrops or earplugs. Discourage the casualty from attempting to perform the valsava manoeuvre.

When a diver descends to a given depth, pressure on the body increases. As this happens, the volume of gas (air) in the lungs decreases by compression. When the diver ascends, the volume of air increases or expands. If the diver ascends rapidly, and doesn't compensate for this expansion by breathing out during surfacing, the expansion of the air exceeds the capacity of the lungs, and causes a rupture of the membrane. This is called a pulmonary barotrauma, and results in a collapsed lung (pneumothorax).
Signs and symptoms of a ruptured lung are; pain in the chest, difficulty breathing, cyanosis, pale clammy skin, restlessness and anxiety. In extreme cases there may be evidence of red, frothy sputum, and associated back pain. The affected lung will collapse and may lead to fatal air bubbles forming in the brain.

A diver presenting with a suspected ruptured lung will require urgent ambulance transport to hospital. First aid is to place the casualty in a position of comfort (generally sitting), and provide reassurance. Should the casualty show an altered level of conscious, put him or her in the stable side position, injured lung down, and be prepared to resuscitate if it becomes necessary.


Facemask squeeze is caused by unrelieved pressure of the diver's facemask during descent. The volume of the air within the mask decreases with depth, and the rubber or latex compound of the mask constricts the tissues of the face. If the air space in the mask is not equalised, eye and facial tissue can be forced into the mask by increased pressure. The diver breathing into the mask through the nose avoids the condition.

This condition also has an effect on the facial sinuses, spaces between the skull and the tissues. Severe facemask squeeze can cause the sinuses and nose to bleed suddenly and copiously - a frightening effect on a diver underwater.

Signs and symptoms of face squeeze may be all, or some, of the following; pain and discomfort around the cheeks and eyes, ruptured capillaries in the whites of the eyes, puffiness around the upper face, headache, sinus pain, and subsequent red mark indicating damaged facial tissues.

First aid is the treatment of any nosebleed (see control of external bleeding), and reference to medical aid if tissue or sinus damage is suspected.


Although nitrogen is regarded as an inert gas, when breathed under extreme pressure it appears to take on an anaesthetic quality. Generally associated with prolonged diving at depths greater than 35 metres, nitrogen narcosis (`the narcs') is thought to be a pressure-related condition that affects nerve fibres.

As a first aid provider, you are unlikely to be involved in the direct effects of `the narcs' as the symptoms are relieved by ascent to the surface. You are more likely to become involved in the secondary effects; injuries or conditions caused to a diver succumbing to nitrogen narcosis.

Diving Emergencies

Signs and symptoms of nitrogen narcosis are; a feeling of euphoria, irrational behaviour, impaired concentration, vertigo, tingling and numbness of the lips, mouth and fingers, and extreme exhaustion. Divers have been observed removing their regulators, masks and fins, or to continue diving to dangerous depths. Affected divers are likely to panic and surface too rapidly, or remain on the bottom, too exhausted to ascend. EACH OF THESE IRRATIONAL ACTIONS CAN CAUSE SERIOUS INJURY OR DEATH.

Should a diver appear ill after a dive, and been witnessed to have shown the signs of "the narcs", he or she should be dissuaded from re-entering the water, and encouraged to rest under observation for recovery. If the diver does not appear to be recovering to your satisfaction, obtain medical aid.

Remember that nitrogen narcosis can be associated with 'the bends' due to the inappropriate actions of the diver at depth.