Search and Rescue Diving

Drowning is reported to be the fourth leading cause of accidental death, whether fresh water, bath tubs, swimming pools, lakes, rivers, streams or ponds. Many of these victims interestingly enough, are a result of the combination of heat exhaustion and alcohol abuse.

The main causes of SCUBA-related accidents can be narrowed down to the following:
• Psychological and physical problems such as hypothermia, hypoxia, etc.
• Lack of oxygen (running out of air).
• Problems with equipment due to operational ignorance or malfunction.
• Environmental conditions (tide, currents etc).
• Encountering ascent problems.
• The buddy system fails.
• Entanglement.

Factors taken into account when a diver is found include whether or not the mask has been flooded and if the snorkel is still attached to the mask. Whether both fins on and if the suit is still intact and if the Buoyancy Control was worn correctly. Regulator depth readings are recorded and the status of the weight belt’s quick- release is checked and the cylinder is monitored for reserve levels.

Understanding the dynamics of the reasons behind search and rescue in this case drowning, assist in applying preventative measures and understanding the circumstances should they occur. Medically, most drowning victims die as a result of a heart attack, the following stages are a precursor to this point:
• The victim tries to keep above the water, trying to draw deep breathes and flailing.
• Panic sets in and leads to hysterical struggling and hyperventilation.
• The victim begins the sink and at this pint will hold their breath as a reflex action causing the oxygen in the lungs to be depleted sooner and the need for more air.
• This urge to breathe due to a carbon dioxide build up after 2-3 minutes of brain depression acute by oxygen deficiency (anoxia) leads to the unconscious victim breathing underwater. The body still responds unconsciously to blocking off the water that is inhaled from the lungs and begins to wretch.
• The water in the lungs results in negative buoyancy and unless the spasm of the larynx closes off the water inhaled (resulting in what is known as a dry drowning) the situation continues to worsen.
• The lack of oxygen sets in affecting brain function and the deprivation affects blood circulation and oxygen transport to the brain and heart thus resulting in cardiac arrest.

There is a very small window period involved where the victim can ‘breathe underwater for about 3 – 4 minutes. 4 -6 minutes later the brain damage begins to occur due to oxygen deprivation. It is for this reason that rescue is not always feasible, considering, response time after notification and deployment and conducting the actual search. This is why it’s important to time when last the victim was seen breathing. The entire process clocks to 15 minutes at the most, except when alcohol intake is involved causing the victim to respond differently on a psychological level. Physically, the negative effect of the substance on the general bodily function will impede a successful resuscitation.

The other exception is due to a fascinating response known as the Mammalian Diving Reflex. This is a primitive psychological response much the same as when a computer reverts to ‘energy saving mode’ - in this case its ‘oxygen saving’. The heart rate reduces and blood flow decreases to the extremities and is redirected to where it is needed most – in the heart and brain. The third response is known as blood shift, whereby blood plasma is dispatched to the chest and positioned as such to protect the lungs from the pressure of a deep water submersion. If this reflex kicks in and the victim:
• is recovered within an hour,
• has not ingested alcohol,
• gets CPR immediately,
• is found in water below 70 degrees F, the cleaner and clearer the better,
• is younger, as the mammalian reflex is stronger in children...

..will stand a much higher chance of recovery.

Search and rescue for recreational divers operate on varying levels of training. Naturally first aid prerequisites are dealt with as a foundation, however the following information will provides examples of guidelines for more in-depth course modules involved.

The dangers of commercial and deep diving require a dive medic onsite for all offshore diving. Dive Medics are trained in the following areas:
• Clinical and practical training in emergency and Hyperbaric medicine
• anatomy and physiology including the functions of the cardiovascular, respiratory and nervous systems
• How to administer blood pressure, detect respiratory rates and listen to lung sounds.
• Operating a Hyperbaric chamber using treatment tables and O2 to treat dive injuries.

A search and rescue technician in the armed forces typically have to have been in the military or a job related trade for four years. Evaluations test psychological and physical limits for endurance. The course modules, length and their nature depend on the institute offering them, varying in countries however basic training can be narrowed down to dealing with the following areas:
• Diving, Arctic survival, winter and summer survival, sea survival, parachuting, crisis scene management, man tracking, flying in a fixed wing aircraft and aerial delivery
• Flying in a rotary wing aircraft and the insertion into land, water and vessel,high altitude indoctrination, aerial photography and weapons skills.
• Swiftwater surface rescue level I, small boat rescue and handling, rapid deployment search and rescue/recovery,
• Homicidal drowning investigations, public safety diving supply, sport rescue diver, phase 1 public safety diving instructor training course, underwater vehicle extrication
• Surface ice rescue level 1 and 2, ice diving search, rescue and recovery and personal watercraft safety and rescue.

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